Lantronix ETS, ETS4P, ETS8P, ETS16P, ETS16PR Reference Manual
...
ETS Reference Manual
For the Lantronix ETS Family of Multiport Device Servers
The information in this guide may change without notice. The manufacturer assumes no responsibility for any errors
which may appear in this guide.
UNIX is a registered trademark of The Open Group. Ethern et is a tra demark of XEROX Corpo ration. DE C and LAT
are trademarks of Digital Equipment Corporation. Centronics is a registered tra demark of Centronics Data Compu t er
Corp. PostScript is a trademark of Adobe Systems, Inc. NetWare is a trademark of Novell Corp. AppleTalk, Chooser,
and Macintosh are trademarks of Apple Computer Corp. LaserJet and Bitronics are trademarks of Hewlett Packard.
Windows is a trademark of Microsoft.
Copyright 2000, Lantronix. All rights reserved. No part of the contents of this book may be transmitted or reproduced
in any form or by any means without the written permission of Lantron ix. Printed in the United States of America.
The revision date for this manual is October 23, 2000.
Part Number: 900-065
Rev. A
WARNING
This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to Part 15 of
FCC Rules. These limits are designed to provide reasonable protection against such interference when operating in a
commercial environment. Th is equipment g enerates, us es, and can r adiate radio fr equency energy, and if not installed
and used in accordance with this guide, may cause harmful interference to radio communications.
Operation of this equipment in a residential area is likely to cause interference in which case the user, at his or her own
expense, will be required to take whatever measures may be required to correct the interference.
Changes or modifications to this device not explicitly approved by Lantronix will void the user’s authority to operate
this device.
Cet appareil doit se soumettre avec la section 15 des statuts et règlemen ts de FCC. Le fonctionn ement est subjecté aux
conditions suiv ant es :
(1) Cet appareil ne doit pas causer une interférence malfaisante.
(2) Cet appareil doît accepter n'importé quelle interférence reìue qui peut causer uneopération indésirable.
i
Contents
1: Introduction............................................................................................................. 1-1
1.1 Product Overview.......................................................................................................................1-1
1.2 Protocol Support.........................................................................................................................1-1
1.3 Terms..........................................................................................................................................1-2
1.4 Server Features ...........................................................................................................................1-2
1.5 How To Use This Manual...........................................................................................................1-5
2: Concepts .................................................................................................................2-1
2.1 Services................................................................................................................... ....................2-1
2.2 Serial Protocols...........................................................................................................................2-1
2.2.1 RS-232........................................................................................................................2-1
2.2.2 RS-423........................................................................................................................2-1
2.2.3 RS-422........................................................................................................................2-2
2.3 Network Protocols......................................................................................................................2-2
2.4 AppleTalk ...................................................................................................................................2-3
2.4.1 Addressing..................................................................................................................2-3
2.4.2 Zones...........................................................................................................................2-3
2.4.3 Name Binding Protocol (NBP)...................................................................................2-4
2.5 LAN Manager.............................................................................................................................2-4
2.5.1 Networking.................................................................................................................2-4
2.6 LAT.............................................................................................................................................2-5
2.7 TCP/IP ........................................................................................................................................2-7
2.7.1 IP Addresses ...............................................................................................................2-7
2.7.2 Telnet..........................................................................................................................2-8
2.7.3 Name Resolution ........................................................................................................2-9
2.7.4 Local Host Table.......................................................................................................2-10
2.7.5 Dynamic Host Control Protocol (DHCP).................................................................2-10
2.7.6 Serial Line Internet Protocol (SLIP).........................................................................2-12
2.7.7 Simple Network Management Protocol (SNMP).....................................................2-13
2.7.8 Reverse Telnet (RTEL).............................................................................................2-13
2.7.9 LPR Support .............................................................................................................2-14
2.7.10 UUCP Support........................................................................................................2-14
2.7.11 TCP/IP Utilities and Commands............................................................................2-14
2.8 LAT and TCP/IP Connectivity.................................................................................................2-15
2.8.1 Connection Methods ................................................................................................. 2-15
2.8.2 Environment Strings.................................................................................................2-15
2.9 NetWare ...................................................................................................................................2-16
2.9.1 Networking...............................................................................................................2-16
2.9.2 Access Lists..............................................................................................................2-16
2.10 Sessions...................................................................................................................................2-17
2.11 PostScript................................................................................................................................2-18
2.12 Modem Features .....................................................................................................................2-18
2.12.1 Remote Configuration ............................................................................................2-19
2.13 Security...................................................................................................................................2-19
Contents
ii
2.13.1 Menu Mode.............................................................................................................2-20
2.13.2 Event Reporting/Logging .......................................................................................2-21
3: Getting Started........................................................................................................ 3-1
3.1 Configuration Methods...............................................................................................................3-1
3.1.1 EZWebCon.................................................................................................................3-1
3.1.2 Using a Web Browser.................................................................................................3-2
3.1.3 Command Line Interface............................................................................................ 3-2
3.2 Entering and Editing Commands................................................................................................3-3
3.3 Restricted Commands.................................................................................................................3-4
3.4 Command Types.........................................................................................................................3-4
3.4.1 Set and Define.............................................................................................................3-4
3.4.2 Show, Monitor, and List.............................................................................................3-4
3.4.3 Clear and Purge...........................................................................................................3-5
3.5 Abbreviating Keywords..............................................................................................................3-5
3.6 Maintenance Issues.....................................................................................................................3-5
3.6.1 Changing the Server Name.........................................................................................3-5
3.6.2 Changing the Server Prompt.......................................................................................3-6
3.6.3 Rebooting the Server..................................................................................................3-6
3.6.4 Restoring Factory Defaults.........................................................................................3-7
3.6.5 Reloading Operational Software.................................................................................3-7
3.7 Editing the Boot Parameters.......................................................................................................3-7
3.8 System Passwords.......................................................................................................................3-8
3.8.1 Privileged Password....................................................................................................3-8
3.8.2 Login Password .......................................................................................................... 3-9
3.8.3 Maintenance Password...............................................................................................3-9
3.9 Configuration Files.....................................................................................................................3-9
3.9.1 Using EZWebCon.....................................................................................................3-10
3.9.2 Without EZWebCon.................................................................................................3-10
4: Server Configuration..............................................................................................4-1
4.1 General Server Parameters..........................................................................................................4-1
4.1.1 Enabling Incoming Connections.................................................................................4-1
4.1.2 Enabling Server-Wide Port Characteristics................................................................4-1
4.1.3 Enabling Announcements...........................................................................................4-2
4.2 AppleTalk Server Parameters.....................................................................................................4-2
4.3 LAT Server Parameters .............................................................................................................. 4-3
4.3.1 Server Identification ................................................................................................... 4-3
4.3.2 Network Timers..........................................................................................................4-3
4.3.3 Node Limit..................................................................................................................4-3
4.4 NetWare Server Parameters........................................................................................................4-4
4.4.1 Routing and Encapsulation.........................................................................................4-4
4.4.2 NetWare Access Lists.................................................................................................4-4
4.5 TCP/IP Server Parameters..........................................................................................................4-5
4.5.1 IP Address...................................................................................................................4-5
4.5.2 Other TCP/IP Parameters ...........................................................................................4-5
4.5.3 Local Host Table.........................................................................................................4-6
4.5.4 Host Limit...................................................................................................................4-6
4.5.5 SLIP............................................................................................................................4-6
4.6 Creating Services......................................................................................................................4-12
Contents
iii
4.6.1 Creating a Simple Service (A Line Printer)..............................................................4-12
4.6.2 Setting Up a Service With Group Codes..................................................................4-13
4.6.3 TCP/Telnet Service Sockets .....................................................................................4-14
4.6.4 Enabling Other Service Options...............................................................................4-14
4.6.5 Setting Up a Modem Service....................................................................................4-15
4.7 Security.....................................................................................................................................4-16
4.7.1 Controlling Incoming Sessions.................................................................................4-16
4.7.2 IP Security Table......................................................................................................4-16
4.7.3 SNMP Security.........................................................................................................4-18
4.8 Event Logging...........................................................................................................................4-18
4.8.1 Configuring Host Types ...........................................................................................4-18
4.8.2 Host Name Formats..................................................................................................4-19
4.8.3 Event Classes............................................................................................................4-19
5: Ports.........................................................................................................................5-1
5.1 Port Commands...........................................................................................................................5-1
5.1.1 Port Access.................................................................................................................5-1
5.1.2 Serial Configuration.................................................................................................... 5-2
5.1.3 Virtual Ports................................................................................................................5-5
5.2 Modems ......................................................................................................................................5-6
5.2.1 Modem Basics ............................................................................................................ 5-6
5.2.2 Modem Wiring............................................................................................................5-7
5.2.3 Baud Rates..................................................................................................................5-8
5.2.4 Modem Configuration ................................................................................................5-9
5.2.5 Modem Result Codes..................................................................................................5-9
5.2.6 Modems with SLIP..................................................................................................... 5-9
5.2.7 Modem Configuration Checklist ..............................................................................5-10
5.2.8 Testing the Modem Configuration............................................................................5-10
5.3 Other Port Characteristics.........................................................................................................5-11
5.3.1 Dialback....................................................................................................................5-11
5.3.2 Dialup .......................................................................................................................5-11
5.3.3 Device Type..............................................................................................................5-12
5.3.4 DTRwait ...................................................................................................................5-12
5.3.5 Group Numbers ........................................................................................................5-12
5.3.6 Interrupts...................................................................................................................5-12
5.3.7 Port Messages...........................................................................................................5-13
5.3.8 Port Names................................................................................................................5-13
5.3.9 Terminal Type ..........................................................................................................5-13
5.4 Security.....................................................................................................................................5-14
5.4.1 Password Restrictions............................................................................................... 5-14
5.4.2 Menu Mode...............................................................................................................5-14
5.4.3 Locking a Port...........................................................................................................5-15
5.4.4 Preventing Access Until DSR Is Asserted................................................................5-15
5.4.5 Automatic Logouts...................................................................................................5-16
5.4.6 Dialback Security......................................................................................................5-16
6: Using the ETS .........................................................................................................6-1
6.1 Logging In and Out.....................................................................................................................6-1
6.1.1 Logging In ..................................................................................................................6-1
6.1.2 Logging Out................................................................................................................6-1
Contents
iv
6.2 Configuring Your Port................................................................................................................6-2
6.2.1 Unsecure Port Commands..........................................................................................6-2
6.3 Connecting to Services...............................................................................................................6-3
6.3.1 Connecting to LAT Services ......................................................................................6-3
6.3.2 Connecting to Telnet Hosts ........................................................................................6-4
6.3.3 Connecting to Local Ports ..........................................................................................6-5
6.3.4 Connecting to Remote Hosts Via Rlogin.................................................................... 6-5
6.3.5 Connecting to the Server from UNIX Hosts...............................................................6-6
6.4 Default Services ..........................................................................................................................6-6
6.5 Session Management..................................................................................................................6-7
6.5.1 Break...........................................................................................................................6-7
6.5.2 Backwards and Forwards............................................................................................6-7
6.5.3 Backward and Forward Switch Keys .........................................................................6-7
6.5.4 Disconnect and Resume..............................................................................................6-8
6.6 Local Server Commands.............................................................................................................6-8
6.6.1 Broadcast ....................................................................................................................6-8
6.6.2 Lock............................................................................................................................6-9
6.6.3 Logout.........................................................................................................................6-9
6.6.4 Test Port......................................................................................................................6-9
6.7 Status Displays............................................................................................................................6-9
7: TCP/IP Host Setup..................................................................................................7-1
7.1 Selecting A Printing Method......................................................................................................7-1
7.2 LPR Printing...............................................................................................................................7-2
7.2.1 LPR Basics..................................................................................................................7-3
7.2.2 LPR on Windows NT 3.5.1 (and later).......................................................................7-4
7.2.3 LPR on AIX Hosts......................................................................................................7-6
7.2.4 LPR on HP Hosts........................................................................................................7-8
7.2.5 LPR on SCO UNIX Hosts..........................................................................................7-8
7.2.6 LPR on Sun Solaris Hosts...........................................................................................7-9
7.3 Reverse Telnet (RTEL).............................................................................................................7-10
7.3.1 Components of RTEL...............................................................................................7-10
7.3.2 Installing Reverse Telnet Software...........................................................................7-10
7.3.3 Queueing with the RTEL Software..........................................................................7-11
7.3.4 Setting up the RTEL Backend Filter ........................................................................7-12
7.3.5 Setting up the RTEL Named Pipe Daemon..............................................................7-14
7.3.6 Creating a BSD Print Queue Using RTELPD..........................................................7-17
7.3.7 Creating a SYSV Print Queue Using RTELPD........................................................7-17
7.3.8 RTEL Troubleshooting............................................................................................. 7-18
7.4 TCP Socket Connections..........................................................................................................7-18
7.5 PostScript Configuration...........................................................................................................7-19
8: NetWare Host Setup............................................................................................... 8-1
8.1 Access Lists ................................................................................................................................8-1
8.2 Licensing NDS............................................................................................................................8-1
8.3 Printing .......................................................................................................................................8-2
8.3.1 Creating NDS Print Queues with PCONSOLE..........................................................8-3
8.3.2 Creating Print Queues with NetWare Administrator..................................................8-4
8.3.3 Creating Bindery Print Queues with QINST..............................................................8-6
8.3.4 Installing a Print Queue Using PCONSOLE..............................................................8-7
Contents
v
8.3.5 Configuring Rprinter ..................................................................................................8-9
8.4 PCL...........................................................................................................................................8-15
8.5 PostScript..................................................................................................................................8-15
8.6 Troubleshooting........................................................................................................................8-15
8.6.1 QINST Print Queue Troubleshooting.......................................................................8-15
8.6.2 NDS Print Queue Troubleshooting...........................................................................8-16
8.6.3 NetWare Host Troubleshooting................................................................................8-18
9: LAT Host Setup.......................................................................................................9-1
9.1 Printing from LAT......................................................................................................................9-1
9.1.1 Printing to an Application Port...................................................................................9-1
9.1.2 Printing to a Service....................................................................................................9-2
9.1.3 Printing PostScript......................................................................................................9-3
9.1.4 Printing Using DCPS Software ..................................................................................9-4
9.1.5 Translating RLAT Jobs to RTEL ...............................................................................9-4
9.2 The ets$configd Download Server .............................................................................................9-5
9.3 Troubleshooting..........................................................................................................................9-6
9.3.1 VMS Printer Troubleshooting ....................................................................................9-6
9.3.2 VMS Host Troubleshooting........................................................................................9-8
10: AppleTalk Host Setup......................... ..... ..... .... ................................. ..... ............ 10-1
10.1 Configuration..........................................................................................................................10-1
10.1.1 Bitronics Interface ..................................................................................................10-1
10.1.2 Macintosh Service Configuration...........................................................................10-2
10.2 Printing from a Macintosh......................................................................................................10-2
10.2.1 Using AppleTalk on UNIX or VMS.......................................................................10-2
10.2.2 Using LaserPrep...................................................................................................... 10-2
10.2.3 Printing Bitmap Graphics.......................................................................................10-2
10.3 Troubleshooting Macintosh Printing......................................................................................10-3
10.3.1 General Troubleshooting........................................................................................ 10-3
10.3.2 Host Troubleshooting.............................................................................................10-5
11: LAN Manager Host Setup...................................................................................11-1
11.1 Printing Methods.....................................................................................................................11-1
11.1.1 DLC .......................................................................................................................11-1
11.1.2 NetBIOS .................................................................................................................11-3
11.2 Windows NT Troubleshooting...............................................................................................11-4
12: Command Reference..........................................................................................12-1
12.1 Overview.................................................................................................................................12-1
12.2 Command Line Interface........................................................................................................12-1
12.2.1 Command Completion............................................................................................12-1
12.2.2 Command Line Editing...........................................................................................12-2
12.3 Attach Port..............................................................................................................................12-2
12.4 Backwards...............................................................................................................................12-4
12.5 Bg............................................................................................................................................12-4
12.6 Broadcast ................................................................................................................................12-4
12.7 Clear/Purge Commands..........................................................................................................12-5
12.7.1 Clear/Purge Dialback..............................................................................................12-5
12.7.2 Clear/Purge Hosts...................................................................................................12-5
Contents
vi
12.7.3 Clear/Purge IPsecurity............................................................................................12-6
12.7.4 Clear/Purge Menu................................................................................................... 12-6
12.7.5 Clear/Purge Protocol NetWare Access...................................................................12-7
12.7.6 Clear/Purge Service................................................................................................12-7
12.7.7 Clear/Purge SLIP ...................................................................................................12-8
12.7.8 Clear/Purge SNMP .................................................................................................12-8
12.7.9 Clear/Purge Telnet Hosts........................................................................................ 12-8
12.8 Close .......................................................................................................................................12-9
12.9 Cls...........................................................................................................................................12-9
12.10 Connect.................................................................................................................................12-9
12.11 Crash 451............................................................................................................................12-11
12.12 Define..................................................................................................................................12-11
12.13 Disconnect ..........................................................................................................................12-12
12.14 Fg........................................................................................................................................12-12
12.15 Finger..................................................................................................................................12-12
12.16 Forwards .............................................................................................................................12-13
12.17 Help.....................................................................................................................................12-13
12.18 Initialize..............................................................................................................................12-14
12.19 Jobs .....................................................................................................................................12-15
12.20 Kill......................................................................................................................................12-15
12.21 LAT.....................................................................................................................................12-15
12.22 List......................................................................................................................................12-15
12.23 Lock....................................................................................................................................12-16
12.24 Logout.................................................................................................................................12-16
12.25 Man.....................................................................................................................................12-16
12.26 Mode...................................................................................................................................12-17
12.27 Monitor ...............................................................................................................................12-17
12.28 Netstat.................................................................................................................................12-17
12.29 Open ....................................................................................................................................12-18
12.30 Ping.....................................................................................................................................12-18
12.31 Purge...................................................................................................................................12-18
12.31.1 Purge SLIP..........................................................................................................12-18
12.32 Remove Queue....................................................................................................................12-19
12.33 Resolve................................................................................................................................12-20
12.34 Resume................................................................................................................................12-20
12.35 Rlogin..................................................................................................................................12-20
12.36 Save.....................................................................................................................................12-21
12.37 Send ....................................................................................................................................12-22
12.38 Set/Define Dialback ............................................................................................................12-23
12.39 Set/Define IPsecurity..........................................................................................................12-23
12.40 Set/Define Logging.............................................................................................................12-25
12.41 Set/Define Menu.................................................................................................................12-26
12.42 Set Noprivileged................................................................................................................. 12-26
12.43 Set/Define Port Commands ................................................................................................12-27
12.43.1 Define Port Access .............................................................................................12-27
12.43.2 Set/Define Port Authorized Groups....................................................................12-28
12.43.3 Set/Define Port Autobaud...................................................................................12-28
12.43.4 Set/Define Port Autoconnect..............................................................................12-29
12.43.5 Set/Define Port Autoprompt...............................................................................12-30
12.43.6 Set/Define Port Autostart....................................................................................12-30
Contents
vii
12.43.7 Set/Define Port Backward..................................................................................12-31
12.43.8 Set/Define Port Break.........................................................................................12-31
12.43.9 Set/Define Port Broadcast...................................................................................12-32
12.43.10 Set/Define Port Character Size.........................................................................12-33
12.43.11 Set/Define Port Command Completion............................................................12-33
12.43.12 Set/Define Port Dedicated ................................................................................12-34
12.43.13 Set/Define Port Dialback..................................................................................12-36
12.43.14 Set/Define Port Dialup......................................................................................12-37
12.43.15 Set/Define Port DSRlogout...............................................................................12-37
12.43.16 Set/Define Port DTRwait..................................................................................12-38
12.43.17 Set/Define Port Flow Control...........................................................................12-39
12.43.18 Set/Define Port Forward ...................................................................................12-40
12.43.19 Set Port Groups................................................................................................. 12-40
12.43.20 Set/Define Port Inactivity Logout.....................................................................12-41
12.43.21 Set/Define Port Local .......................................................................................12-41
12.43.22 Set/Define Port Loss Notification.....................................................................12-42
12.43.23 Set/Define Port Menu.......................................................................................12-43
12.43.24 Define Port Modem Control.............................................................................12-43
12.43.25 Set/Define Port Name.......................................................................................12-44
12.43.26 Set/Define Port Parity.......................................................................................12-44
12.43.27 Set/Define Port Passflow..................................................................................12-45
12.43.28 Set/Define Port Password .................................................................................12-45
12.43.29 Set/Define Port Preferred..................................................................................12-46
12.43.30 Set/Define Port Printer......................................................................................12-48
12.43.31 Set/Define Port Queue......................................................................................12-48
12.43.32 Set/Define Port Remote Configure...................................................................12-49
12.43.33 Set/Define Port Security ...................................................................................12-49
12.43.34 Set/Define Port Session Limit ..........................................................................12-50
12.43.35 Set/Define Port Signal Check...........................................................................12-50
12.43.36 Set/Define Port SLIP........................................................................................12-51
12.43.37 Set/Define Port Speed.......................................................................................12-51
12.43.38 Set/Define Port Stop......................................................................................... 12-52
12.43.39 Set/Define Port Telnet Pad ...............................................................................12-53
12.43.40 Set/Define Port Termtype.................................................................................12-53
12.43.41 Set/Define Port Type........................................................................................12-54
12.43.42 Set/Define Port Username ................................................................................12-54
12.43.43 Set/Define Port Verification .............................................................................12-55
12.44 Set Privileged/Noprivileged................................................................................................12-56
12.45 Set/Define Protocols Commands........................................................................................12-56
12.45.1 Define Protocols AppleTalk ............................................................................... 12-56
12.45.2 Define Protocols IP.............................................................................................12-57
12.45.3 Define Protocols LAN Manager.........................................................................12-58
12.45.4 Set/Define Protocols LAT..................................................................................12-58
12.45.5 Set/Define Protocols NetWare ............................................................................12-59
12.46 Set/Define Server Commands.............................................................................................12-62
12.46.1 Set/Define Server Announcements.....................................................................12-62
12.46.2 Set/Define Server Bootgateway..........................................................................12-63
12.46.3 Set/Define Server BOOTP..................................................................................12-63
12.46.4 Set/Define Server Broadcast...............................................................................12-63
12.46.5 Set/Define Server Buffering...............................................................................12-64
Contents
viii
12.46.6 Set/Define Server Circuit Timer.........................................................................12-64
12.46.7 Set/Define Server Console..................................................................................12-65
12.46.8 Set/Define Server Domain..................................................................................12-65
12.46.9 Set/Define Server DHCP....................................................................................12-65
12.46.10 Set/Define Server Gateway...............................................................................12-66
12.46.11 Set/Define Server Groups ................................................................................12-66
12.46.12 Set/Define Server Host Limit ...........................................................................12-67
12.46.13 Set/Define Server Identification.......................................................................12-67
12.46.14 Set/Define Server Inactivity Timer...................................................................12-68
12.46.15 Set/Define Server Incoming .............................................................................12-68
12.46.16 Set/Define Server IPaddress .............................................................................12-69
12.46.17 Set/Define Server Keepalive Timer..................................................................12-70
12.46.18 Set/Define Server Loadhost..............................................................................12-70
12.46.19 Set/Define Server Lock.....................................................................................12-71
12.46.20 Set/Define Server Login Password...................................................................12-71
12.46.21 Set/Define Server Maintenance Password........................................................12-72
12.46.22 Set/Define Server Multicast Timer...................................................................12-72
12.46.23 Set/Define Server Name ...................................................................................12-73
12.46.24 Set/Define Server Nameserver .........................................................................12-73
12.46.25 Set/Define Server NetWare Loadhost ..............................................................12-74
12.46.26 Set/Define Server NetWare Printserver............................................................12-74
12.46.27 Set Server NetWare Reset ................................................................................12-75
12.46.28 Set/Define Server Node Limit ..........................................................................12-75
12.46.29 Set/Define Server Password Limit....................................................................12-75
12.46.30 Set/Define Server Privileged Password............................................................12-76
12.46.31 Set/Define Server Prompt.................................................................................12-76
12.46.32 Set/Define Server Queue Limit ........................................................................12-77
12.46.33 Set/Define Server RARP ..................................................................................12-78
12.46.34 Set/Define Server Reload .................................................................................12-78
12.46.35 Set/Define Server Retransmit Limit .................................................................12-78
12.46.36 Set/Define Server Rlogin..................................................................................12-79
12.46.37 Set/Define Server Secondary............................................................................12-79
12.46.38 Set/Define Server Serial Delay.........................................................................12-79
12.46.39 Set/Define Server Service Groups....................................................................12-80
12.46.40 Set/Define Server Session Limit.......................................................................12-80
12.46.41 Define Server Silentboot...................................................................................12-81
12.46.42 Set/Define Server SLIP Password.................................................................... 12-81
12.46.43 Set/Define Server Software ..............................................................................12-82
12.46.44 Set/Define Server Startupfile............................................................................12-82
12.46.45 Set/Define Server Subnet Mask........................................................................12-83
12.46.46 Set/Define Server UUCP..................................................................................12-84
12.47 Set/Define Service Commands...........................................................................................12-84
12.47.1 Set/Define Service..............................................................................................12-84
12.47.2 Set/Define Service AppleTalk............................................................................12-85
12.47.3 Set/Define Service Banner..................................................................................12-85
12.47.4 Set/Define Service Binary..................................................................................12-86
12.47.5 Set/Define Service DLC.....................................................................................12-86
12.47.6 Set/Define Service EOJ ......................................................................................12-86
12.47.7 Set/Define Service Formfeed..............................................................................12-87
12.47.8 Set/Define Service Identification........................................................................12-87
Contents
ix
12.47.9 Set/Define Service LAN Manager...................................................................... 12-88
12.47.10 Set/Define Service LAT ...................................................................................12-88
12.47.11 Set/Define Service NetWare.............................................................................12-88
12.47.12 Set/Define Service Password............................................................................12-89
12.47.13 Set/Define Service Ports...................................................................................12-89
12.47.14 Set/Define Service PostScript ...........................................................................12-90
12.47.15 Set/Define Service PSConvert..........................................................................12-90
12.47.16 Set/Define Service RTEL.................................................................................12-90
12.47.17 Set/Define Service SOJ.....................................................................................12-91
12.47.18 Set/Define Service TCPport .............................................................................12-91
12.47.19 Set/Define Service Telnetport...........................................................................12-92
12.47.20 Set/Define Service Virtual................................................................................12-92
12.48 Set Session Commands.......................................................................................................12-93
12.48.1 Set Session Delete...............................................................................................12-93
12.48.2 Set Session Echo.................................................................................................12-93
12.48.3 Set Session Interactive........................................................................................12-94
12.48.4 Set Session Newline ...........................................................................................12-94
12.48.5 Set Session Passall..............................................................................................12-95
12.48.6 Set Session Passthru ...........................................................................................12-95
12.49 Set/Define SLIP..................................................................................................................12-95
12.49.1 Set SLIP..............................................................................................................12-96
12.49.2 Define SLIP........................................................................................................12-97
12.50 Set/Define SNMP ...............................................................................................................12-98
12.51 Set/Define Telnet Hosts......................................................................................................12-99
12.52 Show/Monitor/List Commands.........................................................................................12-100
12.52.1 Show/Monitor/List Dialback ............................................................................12-100
12.52.2 Show/Monitor/List Hosts..................................................................................12-100
12.52.3 Show/Monitor/List IPsecurity ..........................................................................12-100
12.52.4 Show/Monitor/List Logging.............................................................................12-101
12.52.5 Show/Monitor/List Menu.................................................................................12-101
12.52.6 Show/Monitor Nodes........................................................................................12-101
12.52.7 Show/Monitor/List Ports..................................................................................12-102
12.52.8 Show/Monitor/List Protocols............................................................................12-104
12.52.9 Show/Monitor Queue........................................................................................12-107
12.52.10 Show/Monitor/List Server..............................................................................12-108
12.52.11 Show/Monitor/List Services...........................................................................12-111
12.52.12 Show/Monitor Sessions..................................................................................12-111
12.52.13 Show/List SLIP...............................................................................................12-112
12.52.14 Show/Monitor/List SNMP..............................................................................12-112
12.52.15 Show/Monitor/List [Telnet] Hosts..................................................................12-113
12.52.16 Show/Monitor Users.......................................................................................12-113
12.52.17 Show Version..................................................................................................12-114
12.53 Source ...............................................................................................................................12-114
12.54 Stty....................................................................................................................................12-115
12.55 Su......................................................................................................................................12-115
12.56 Telnet................................................................................................................................12-115
12.57 Test Loop..........................................................................................................................12-116
12.58 Test Port............................................................................................................................ 12-116
12.59 Test Service.......................................................................................................................12-117
12.60 Unattach Port ....................................................................................................................12-118
Contents
x
12.61 Unlock Port.......................................................................................................................12-119
12.62 Who...................................................................................................................................12-119
12.63 Zero Counters ...................................................................................................................12-119
A: Contact Information...............................................................................................A-1
A.1 Problem Report Procedure........................................................................................................A-1
A.2 Full Contact Information...........................................................................................................A-1
B: Troubleshooting.....................................................................................................B-1
B.1 Power-up Troubleshooting........................................................................................................B-1
B.2 DHCP Troubleshooting.............................................................................................................B-1
B.3 BOOTP Troubleshooting..........................................................................................................B-2
B.4 RARP Troubleshooting.............................................................................................................B-2
B.5 Modem Configuration Checklist...............................................................................................B-2
C: Updating Software .................................................................................................C-1
C.1 Obtaining Software ...................................................................................................................C-1
C.2 Reloading Software ...................................................................................................................C-2
C.3 Troubleshooting Flash ROM Updates......................................................................................C-4
Glossary
Index
1-1
1: Introduction
1.1 Product Overview
The Lantronix ETSs (ETS4P, ETS8P, ETS16P, ETS16PR, ETS32PR, and ETS422PR) are Multiport
Device Servers that provide shared network access to terminals, devices, console ports, and printers for a
variety of network protocols and operating systems. The ETS supports the TCP/IP, IPX (NetWare), Local
Area Transport (LAT), AppleTalk (EtherTalk), and Microsoft LAN Manager protocols.
Lantronix server s store thei r executabl e software i n Flash (rewri table) ROM, mea ning that they do not hav e
to download software from a host each time they boot. Software must only be downloaded when a new
software version becomes available. See Appendix D for more information.
Note: In this manual, all servers will be referred to as “the ETS” unless a distinction
needs to be made between models.
1.2 Protocol Support
The ETS supports five industry-standard network protocols:
TCP/IP
TCP/IP is a widely-used protocol that can be run on networks with Macintoshes, PCs, and Unix
workstations. Server support includes Telnet, Rlogin, DNS, and the LPR and RTEL printing systems.
NetWare (IPX/SPX )
NetWare allows devices attached to the ETS to act as networked printers. The ETS s upports all NetWare frame types: Ethernet v2, Native Mode (802.3), 802.2, and 802.2 SNAP. In addition, it supports both Bindery mode and NetWare Directory Services (NDS).
Local Area Transport (LAT)
LAT is a protocol developed by Digital Equip ment Corporati on for local netwo rk terminal connec tions and is supported on almost all Digital operating systems. It provides both logins to remote
hosts and host-initiated print spooling.
AppleTalk
AppleTalk allows networked Apple Macintosh computers to see devices attached to the ETS and
access them as they would any networked printer.
LAN Manager
The ETS allows devices on LAN Manager ne tworks to access networke d printers. Systems runni ng
Windows NT can access the devices using the Digital Network Port for Windows NT or the NetBIOS protocol.
Terms Introduction
1-2
1.3 Terms
In this manual, the following terms are used to describe parts of a network. See the Glossary for more
detailed explanations of these terms.
host A computer, sometimes referred to as a CPU, attached to the network. The
term host
node Any intelligent device directly connected to the Ethernet network and having
its own Ethernet addre sses, such a s a host, an Ethernet p rinter, or a t erminal o r
print server. Devices connected to the ETS are not nodes.
service A resource that can be acc essed local ly or via the net work. For example, a host
is a service to which terminals can connect. The ETS can offer its attached
printers and modems to the network as services.
session A logical connectio n to a ser vi ce. A t ypi cal session is a terminal connect ed to
a host through the terminal server.
Local mode The ETS user interface, which is used to issue configuration and session
management commands and establish sessions with services.
1.4 Server Features
AppleTalk Support
The ETS provides Ethernet a cce ss to attached laser pri nte rs ; ETS p ri nt s er vic es a ppe ar i n t he Mac intosh Chooser window li ke any other pr inter on the ne twork. Bi-directi onal communication (either
a serial or IEEE 1284 parallel interface) is required.
LAN Manager Support
The ETS can be configured to appear as a print node to other LAN Manag er nodes. Suppo rted systems include Windows NT and Windows 95.
LAT and Digital Compatibility
The ETS supports LAT and TSM/NCP, making it fully compatible with most Digital Equipment
Corporation operating environments.
NetWare Support
The ETS is used primar il y f or pr int serving. The ETS c an als o be c onf igured and logged int o fr om
a NetWare fileserver, and can function as a print node for other NetWare fileservers.
TCP/IP and UNIX Compatibility
Almost all UNIX systems support Telnet, an established industry standard. Telnet can be used for
interactive se ssions, or fo r logging int o the server to issu e configurat ion commands. UNIX system s
generally implement Rlogin as well, unless security considerations dictate that it be disabled at a
particular site. Support for domain name servers, network gateways, SLIP access, and a local domain name are all provided. In addition, IP security can be enabled to control access to the server.
Introduction Server Features
1-3
Connectivity
The Server connects ter mina ls dir ectl y to the net work , which conse rv es physi cal port s on th e host,
allows the terminal to acc ess more than one host, and simplifies terminal cabling .
Multiple Session Support
Users can open multiple out goi ng LAT, Rlo gin , and Telnet sessions, and can eas il y swit ch among
active sessions. Up to eight s essions are supported p er connected terminal. Each session can be connected to any host and can use any supported protocol.
Load Balancing
If a LAT service is provided by more than one node, the server chooses the least busy service for
the connection. This helps balance CPU usage and provides better user response times.
Small Size
The small, attract ive case is des igned to fit int o any office env ironment. Becaus e there is no int ernal
fan, the ETS operates silently.
Ease of Use
The server’s Local mode su pports command li ne editing, command line recal l, and command completion. An extensive Help facility is also provided.
Easy Configuration
The EZWebCon utility (p rovide d on CD-ROM) allows users to c onfigu re th e ET S from a any h ost
machine running the Java Vir tual Machine (JVM). It also al lows remote host logins into the Server,
which are similar to Telnet and LAT logins.
Note: You must be Supervisor to run the EZWebCon utility on a NetWare client.
Dialback ports, which allow manag ers to improve secur ity for dial-in mode m users. A menu mode,
which enables managers to tailor which individual commands users are allowed to use.
Remote Configu ration
The ETS can be logged into and remotely configured using one of the following methods:
❍ Digital’s NCP and TSM facilities
❍ The Telnet c onsole port, similar to the N CP remote console
❍ The network login feature, which allows managers to log into the ETS via TCP/IP, LAT, and
NetWare.
❍ EZWebCon, a configuration applic ation that ru ns on any host computer running the Java Virt ual
Machine (JVM).
Server Features Introduction
1-4
Command Line Interface
A simple but powerful command interface is provided for both users and system managers. The
ETS operating code is downloaded automatically at power-up, making software upgrades as easy
as copying a file.
The ETS stores its ope rati ng sof tware permane ntly on- board, so i t doe s not need to downloa d code
unless new versions bec ome available. Servers ca n also be configured to requ est a downloaded configuration file at boot time.
The Command Reference chapter o f this r eference manual desc ribes the commands a vailable in the
ETS’s local command line mode. These commands control port and server configuration, session
management, and other tasks. Ports can be se t to secur e to allow onl y a subset of the commands. In
addition, a menu mode i s prov ided so that users will n ot have to le arn th e Se rver c ommand set , but
can instead choose from a table of commands.
Note: See the Command Reference for more information on the command line,
command recall, and command completion features.
Context-Sensitive Help
Context-sensiti ve on-line help is ava ilable at any poin t. You may type “HELP” b y itself for over all
help, “HELP command” for help on a specific command, or a partial command li ne f oll owed by a
question mark for help on what is appropriate at that particular point.
Note: See Help on page 12-13 for more information.
Host-Initiated Connections
The ETS may be configured to provide its attached devices as services to other nodes, allowing
hosts to share pr int er s and modems. AppleTalk, LAN Mana ger , LAT, Net Wa re, and TCP/IP hosts
can queue jobs to ETS services simultaneously. The optional RTEL host software provides both
printer backend access and a named pipe interface to the ETS from TCP/IP hosts.
IPX Redirector
The IPX Redirector i s an a pplica tion that allows PCs on an IPX net work to share mode ms conne cted to the server using Micros oft Windows or DOS communi cations sof tware that sup ports the INT
14 or NASI redirector interface. With the help of the Redirector, PC users can dial out, connect to
a modem available as an ETS service, and connect to a remote host.
Security
The ETS includes several configurable security features. They include:
❍ Group codes, which allow the ETS to act as a filter to limit the user’s knowledge of, and access
to, specific services.
❍ Automatic session logouts when a port is disconnected or a device is turned off.
❍ Password protection for privileges, ports, services, maintenance commands, and the remote
console.
❍ The ability to secure certain ports, which prevents them from issuing privileged commands and
giving them a limited view of the network.
❍ The ability of an individual user to lock his or her port, as well as specify the password that will
unlock it.
Introduction How To Use This Manual
1-5
❍ An IP security table, which allows the server manager to restrict incoming and outgoing TCP/IP
connections to certain ports and hosts. This allows managers to restrict Server access to a
particular local network segment or host. It also allows restrictions for SLIP access to the
network.
DHCP Support
The Server can obtain an IP address from a DHCP server at boot time.
SNMP Support
The ETS supports the Simple Network Management Protocol (SNMP), which can be used by network managers to monitor net work load and e rror condi tions. No enter prise-s pecific MIBs ar e supplied by Lantronix.
Diagnostics
Power-up and interactive diagnostics help system managers troubleshoot network and serial line
problems.
1.5 How To Use This Manual
The rest of the chapters in this manual describe the features and commands of the ETS. Information is
broken down as follows:
◆ Chapters 2 through 6 cover general functionality:
◆ Chapter 2, Concepts, explains the basic ideas behind ETS operation.
◆ Chapter 3, Getting Started, explains available configuration methods, as well as steps needed for
reconfiguration and maintenance operation.
◆ Chapter 4, Server Configuration, explains server-wide configuration options, including protocol-
specific configuration and security issues.
◆ Chapter 5, Ports, details the port- specific confi gurat ion opt io ns, inc luding seri al por t par ameters and
modem-related commands.
◆ Chapter 6, Using the ETS, introduces end-users to the Server. It also explains how to use the Server
interactively.
◆ Chapters 7 through 11 cover protocol-specific issues and troubleshooting:
❍ Chapter 7 covers TCP/IP Host Setup.
❍ Chapter 8 covers NetWare Host Setup.
❍ Chapter 9 covers LAT Host Setup for VMS.
❍ Chapter 10 covers AppleTalk Host Setup.
❍ Chapter 11 covers LAN Manager Host Setup.
How To Use This Manual Introduction
1-6
◆ Chapter 12, Command Reference, lists the ETS command set in detail, including syntax, options,
errors, examples, and where to find related information.
◆ Appendices provide supplementary information, including Technical Support contact information,
troubleshooting tips, and pinout information.
Note: Installation and cabling are covered in your Server’s Installation Guide.
2-1
2: Concepts
The ETS provides two major functions: outgoing sessions, which are basically interactive connections to
other nodes, and incoming connections to services, such as printer and modem support.
2.1 Services
Services are the basic method of co nnecting to t he ETS from any hos t or another server. In ge neral, a service
is required on th e ETS before any job or connect ion queuei ng will t ake pla ce. See the Ser ver Config uration
chapter for details on creating and using services.
2.2 Serial Protocols
The ETS models support RS-423 and RS-422 se rial protocols. I n addition, the y are compatible wi th RS-232
devices.
2.2.1 RS-232
The RS-232 line interface standard is a single-ended peer-to-peer interface. Today’s personal computers
typically have at least one RS-232 serial port. It is the most common serial protocol used today.
RS-232 is used for connecting devices across short distances, at speeds up to 230.4 kb/s. Faster speeds
require shorter cabli ng to ensure error-fr ee communicati ons. The maximum cable lengt h at a given speed is
determined by many factors, i ncludi ng the immedi ate el ectrica l env ironment and t he quali ty of cab le used,
but is usually less than 10 meters at high speeds.
Lantronix MSS models have RS-232 ports. RS-232 devices are interoperable with RS-423 devices.
2.2.2 RS-423
All of the ETS models support the RS-423 line interface standard. RS-423 devices are interoperable with
RS-232 devices. That is, RS-232 ports can receive data reliably from RS-423 ports and vice-versa.
The main difference between RS-423 and RS-232 is that RS-423 employs lower voltage signaling and
differential receivers. RS-423 still uses single-ended transmitters for compatibility with RS-232 receivers.
RS-423 is generally rated at higher speeds over longer cabling runs than RS-232. Maximum data rates of
230.4 kb/s are possible on ETS-PR models, and 115.2 kb/s is the maximum on ETS-P models.
Network Protocols Concepts
2-2
2.2.3 RS-422
The ETS422PR supports RS -422 on all of it s p orts. RS-422 i s dif ferent fr om RS-232 or RS-42 3 in t hat i t is
a differential or balanced line interface standard. It is designed for longer cabling distances (approaching
4,000 feet) in noisie r electrical environments , and it can be used in mult i-drop networks with one drive r and
up to ten receivers.
The maximum speed of the RS-42 2 port s on t he E TS422PR is 230.4 k b/s, as with RS-4 23, but this rate can
be sustained over longer cable runs than possible on RS-232 or RS-423 connections.
RS-422 ports are interoperable with RS-423 ports, but not with RS-232. When connecting an RS-422 port
to an RS-423 port, you must be sure that your connector cable is properly configured. Please consult the
connector pinout drawings in Appendix C before making a connector cable.
2.3 Network Protocols
A network protocol describes the data contained in Ethernet packets. The network protocols provided by
the ETS are completely separa te , other than the use of the Ethernet data lay er. The following figure shows
the protocol stacks supported by the ETS.
Figure 2-1: Supported Network Protocols
There are three different Ethernet frame formats, one of which is subdivided:
◆ What is typically called Ethernet is technically referred to as Ethernet v2. This is the default frame
type for most TCP/IP, LAT, and MOP/NCP protocol stacks. It can also be used for NetWare.
◆ The IEEE 802.2 frame format comes with either a regular or a SNAP SAP (Service Access Point).
AppleTalk uses the SNAP format by default. Both types can be used by NetWare.
◆ NetWare 2.x and 3.x stations, by def ault, do not use any of these fr ame types. They use a native mode
format that is being phased out.
AppleTalk LAN Manager LAT NetWare TCP/IP
Printer
Access Protocol
SMB LAT NCP Telnet/ Rlo-
gin/ RTEL/
lpd
ATP NetBEUI SPX TCP
DDP IPX IP
Ethernet/IEEE 802.3 Data Layer
Concepts AppleTalk
2-3
2.4 AppleTalk
AppleTalk is a protocol used primarily by Apple Macintoshes to access network resources such as file
servers and printers. AppleTalk is also available for UNIX, NetWare, and other operating systems. The
AppleTalk protocol c an be run over Etherne t (EtherTalk), Token Ring (TokenTa lk), or LocalTal k, which is
a medium speed network type built into every Macintosh. These various network media can be connected
with AppleTalk routers to allow all nodes to communicate with one another. The AppleTalk protocol
supports features such as file sharing and security in addition to printing.
The ETS supports only the Printe r Access Protocol (PAP) and th erefo re canno t creat e outgoi ng AppleTa lk
sessions—only incoming pri nt requests are accepted. Any services on the ETS with AppleTalk enabled will
show up as LaserWriters in Macintosh Chooser windows and are associated with an available zone
(explained in Section 2. 4.2) . User s who s el ect a ETS service as their LaserWrit er wil l ha ve th ei r pr int jobs
forwarded to the ETS for printing, or for queueing if the print port on the ETS is in use or otherwise
unavailable.
AppleTalk printing is different from printing in other protocols. There are standard Macintosh drivers
provided for specific Apple printer types, such as LaserWriters and ImageWriters, but there are no plain
ASCII line print ers by default. ASCII jobs are converted into PostScript (for la se r p rinters) or bitmaps (for
ImageWriters) when printed. Only laser printer devices are supported by the ETS under AppleTalk.
The Macintosh client will need to query the printer about status, so only laser printers that reply to these
interactive PostScript requests can be used. The ETS parallel ports support Bitronics mode, provided the
attached laser printer also implements it.
2.4.1 Addressing
AppleTalk provides for dynamic node addressing, a llowing a node to choose its ad dress at boot time. It will
send network packets to the other nodes to avoid choosing a node ID already in use. A node can also
discover its network number by listening for AppleTalk router broadcasts; if none are heard, a default
network number is chos en. The ETS will save zon e/net work/nod e ID t ripl ets in pe rman ent memor y, which
reduces traffic at rebo ot time, alt hough the ETS Appl eTalk addre ss may change ac ross boots in response to
any network changes.
Network numbers are conf igure d in the r outer s, so the o nly Appl eTalk confi gurat ion s uppo rted by the ETS
is the specification of a zone name other than the default. D ue to the generally non-configu rable natur e of
AppleTalk, most AppleTa lk devices are t ruly “plug-a nd-play”— they c an be powered up and used right out
of the box.
2.4.2 Zones
Zones are arbitra ry groupin gs of AppleTal k nodes used to orga nize reso urces int o groups that are e asier fo r
users to understand. For example, a college may organize zones around departments, like Math
Department and Physics Department. Zones allow users to sift through large numbers of nodes by
choosing those groups they are fami liar with regar dless of the o rganization of t he network. In ge neral, zones
need not have a correlation to physical or network location, thus any node can declare itself a member of
any single zone.
LAN Manager Concepts
2-4
Zones, like nodes, origin ate from and are confi gured on AppleTal k routers. One zone on each network wil l
be chosen by the router as the defaul t zone. If ther e are no Apple Talk rou ters on the network, th ere wil l be
only one zone (the default zone) of which all nodes are members. If no zone name has been previously
defined on the ETS, or if the de fined zone is no longe r valid, the ETS wil l join the defa ult zone and no other
configuration is needed. The ETS can be placed in a different zone with the Define Protocols AppleTalk
command. Each time the ETS is booted, or when its zone is changed, it will verify the zone name with a
router.
2.4.3 Name Binding Protocol (NBP)
NBP is used by AppleTalk to advertise resources, such as printers and fileservers, to the network. Any
resource that othe r user s can access will have NBP i nformat ion t hat must be co mmunic ated t o othe r nodes .
The items in the Chooser window reflect the NBP resources on the network.
NBP and the Chooser organize re sources by t hree level s: name, type , and zone. Names ar e arbitrary strings
assigned by users , such as Kathy or MyPrinter. T ypes are generi c classes o f resources , such as Ma cintos h
IIci and LaserWriter. Zones, mentioned previously, are collections of nodes on the network. Typical
Macintosh NBP information might be [Kathy, Macintosh IIci, Accounting] for the name, type, and zone,
respectively. A serv ice offered by the E TS called MyPrinter that has AppleTalk enable d and that is located
in the Engineering zone would have an NBP description of [MyPrinter, LaserWriter, Engineering]. If the
LaserWriter resource in the Engineering zone were selected in the Chooser, one of the resources shown
would be the MyPrinter service offered by the ETS.
The NBP type LaserWriter designates a PostScript printer, so nodes printing to printers of type
LaserWrite r assume that th e printer sup ports PostSc ript. Care must be taken to attach only PostScript
printers to ETS ser vices with AppleTalk e nabl ed , an d t o d isa ble AppleTalk on servi ce s t hat do not support
PostScript printers. It is not possible to print to non-PostScript printers (for example, ImageWriters and
StyleWriters) from a Macintosh via the ETS.
2.5 LAN Manager
LAN Manager is based on the NetBIOS pr otocol. It is use d by several PC-b ased operatin g systems, notabl y
OS/2, Windows NT, and Windows for Workgroups , althou gh LAN Manage r serv ers have been written f or
HP and Sun workstations. The ETS i mplements only en ough of the NetBIOS protoc ol stack to provi de print
services to nodes; no interactive logins are allowed.
The ETS also implements the straightforward and easy to use DLC printer protocol typically used by HP
laser printers. You must se lect the hardware addre ss of the ETS as the target for t he print job. DLC operation
is only supported under Windows NT. DLC does not provide queueing on the ETS, nor does it allow
printing to more than one service on the ETS.
2.5.1 Networking
NetBIOS is not a routable protocol, so the ETS can only communicate with local nodes or nodes that are
accessible via a gateway capable of bridging the NetBIOS data.
Concepts LAT
2-5
LAN Manager node lookups take a text resource name and resolve it into a hardware address. For this
reason, node and resource names must be unique on the network, and the ETS will print an error message
if any configuration that violates this rule is attempted.
Note: NetBIOS can be run over TCP/IP, but the ETS does not support this mode of
operation.
2.6 LAT
Digital Equipment Corpor ation’s LAT ( Loca l Area Trans port) netw orkin g software is d esigne d to eas e the
process of accessing and managing local area networks.
LAT is significantly different from other protocols in two important ways. First, LAT is not routable. There
is no way to divide LAT networks into smaller subnet works and use routers to reduce tra ffic between nodes.
Second, LAT is a timer-driven protocol. Packets are expected at certain intervals, and the protocol cannot
adapt to slow network lin ks dynamically. Fo r these reaso ns, LAT traffic over wide areas is ty pically carri ed
inside (or encapsulated in) TCP/IP or IPX/SPX packets. The latter two protocols are fully routable, and
can handle wide-area, slow network links.
Note: If LAT is bridged across slow links, session time-outs and errors are likely.
LAT software is built around the concept of services. A service may be provided by a dedicated device,
such as a printer, or by a ne twork host. A device t hat offers one or more se rvices, such as your ETS, is called
a node.
Services have names, and there can be more than one service on a network with the same name. For
example, you could attach eight modems to a server and set up the service modem to use ports 1-8; a user
who typed Connect Modem wo uld not nece ssarily know which port would be used fo r the connec tion. Note
that if a service is provided by the lo cal ETS and a lso a by r emote node, there i s no guaran tee that a connect
command issued locally would result in a connection to the local service (although this can be explicitly
requested).
LAT Concepts
2-6
In general, all ser vices offered by the ETS are ass ociated with one or more ports; exceptions t o this rule will
be noted later. Figure 2-2 shows an example of services offered on a network.
Figure 2-2: Example of Network Services
Nodes advertise their services to the network by broadcasting occasional messages about them. These
messages, referred to as multicasts, contain the node’s name and its list of services. By monitoring
multicast messages, all hosts on the network know what nodes and services are available and can provide
this information to their interactive users. The Show Services and Show Nodes commands display this
information.
LAT multicast messages contain a rating for each service offered. Ratings range from 0 to 255; 0 means
the service is unavailable, while 255 means the service is available and has no current users. Ratings for a
given service may cha nge over t ime. For ex ample, t he ratin g for a c omputer accept ing logi ns will g enerall y
change as its workload cha nges. Conv ersel y, rati ngs for a modem are t ypical ly eit her 0 ( in use) or 255 (no t
in use). In the example above, the server with eight modems attached will continue to advertise that the
service “modem” is available (a 255 rating) until all eight modems are in use (a 0 rating).
Service ratings may concern even casual users, since they are used to determine which service a user will
be connected to whenever there is a choice. For example, if a user types Connect Hub and five nodes
offer service hub, the user will be connected to the least busy node automatically. In the case mentioned
above, where both the local ETS and a remote node offered the same service, the ratings determine which
node will service the connection attempt.
Another major netwo rk management featur e of LAT is the concept of service groups. Eac h port on the ETS
and each service on the network can be thought of as belonging to one or more groups. When a user or
device requests a service connection, the LAT host will check to see if the groups to which the requester
belongs match those of the r equested s ervice. If any group number is common to both the request er and the
service, the connection attempt continues. If there are no common group numbers, the connection attempt
fails.
Note: There may be additional access restrictions on the service, such as password
protection.
Node Vax2, with
service Vax2
(logins to other
users)
Node Phred, a computer
offering services
"LaserPrinter" (for
printing) and "Phred"
(for logins)
Node Server_1, offering
service "modem"
01
PWR OK NET RCV XMT
EPS4
LANtronix
Concepts TCP/IP
2-7
Suppose Bob is logged into port 4 on his ETS and the server manager has given port 4 access to groups 1,
7, 13, and 105. Bob, or anyone else using port 4, can only access services that have one of those group
numbers. Suppose Bob wishes to access a modem on a different server. If the server to which the modem
is attached allows access to groups 8, 12, 16, 42, and 105; Bob will be allowed to use the modem because
he and the modem service have group 105 in common.
Note: See Set/Define Port Authorized Groups on page 12-28 and Set/Define Server
Service Groups on page 12-80 for more information.
Group numbers also are useful to nodes because each node only needs to pay attention to multicasts that
involve its users’ groups. As a result, groups can hide services that would otherwise be visible. The server
manager can also hide se rvices from a set of port s. Setting up and managi ng services and groups i s discussed
in more detail in the Server Configuration chapter, n ext.
ETS units used in the LAT environment support remote configuration of server ports by VMS hosts. This
feature of the LAT softwar e allows the serve r to implement VMS commands that chang e a user’s “termin al
line.” For instance, if user Bob con nects to a VMS host and ty pes the command Set Term inal/Spe ed=2400,
the speed will be changed on the host and the host will ask the ETS to change the “real” terminal line (in
this case, Bob’s ser ia l port on the server). Thi s feature supports chan ges to parity and flow control as well.
Note: Remote control can b e disa bled; see Set /Defi ne Port Remote Co nfigur e on pag e
12-49.
2.7 TCP/IP
2.7.1 IP Addresses
Every TCP/IP node on a network has an IP address, which is unique to that network and an Ethernet
Address, which is unique across all hardware in the world. The IP address provides information needed to
forward packets across multiple networks, if necessary.
The address is of the form n .n.n.n, where each n is a number from zero to 254, as in 192.0.0.1 . The exception
is that there cannot be a zero in the last segment of the address.
Note: The number 255 is strictly reserved for broadcast packets.
A unique IP address must be specif ied on the ETS before any of the TCP/IP funct io nal it y is available. See
your Installation Guide for more information on configuring the IP address.
A DHCP server can be used to tempora rily assign a leased IP ad dress to the ETS. See Dynamic Host Control
Protocol (DHCP) on page 12-10 for more information.
TCP/IP Concepts
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2.7.2 Telnet
Telnet is an industry-standard network protocol. Networks that support Telnet can (and do) stretch for
thousands of miles a nd cont ain t housands of ho sts. Th e theo ry behi nd Tel net i s that a use r anywhe re on the
network can access a for ei gn host and start a ter mina l session. The user does not hav e t o wor ry ab out what
kind of computer or operati ng system he is dealing wit h, and the remote host does not need to know the type
of terminal the user is using. Telnet accomplishes this compatibility with the virtual terminal: any Telnet
connection looks the same from both sides of the network. Figure 2-3 illustrates this concept.
Figure 2-3: ETS Network Telnet Example
2.7.2.1 Telnet Connections
All terminals on the network can access all hosts, but do not need to know (nor can they know) the host’s
exact hardware type. Theoretically, terminal 4 in the example above could establish a Telnet session with
host Phred, and would see t he same type of sessi on as it would with a direct terminal connection to terminal
5. Phred, the CPU, will also treat terminal 4 as if it were directly connected.
A Telnet connection begin s with both par ties in the c onnection assuming t hat the other termina l is “dumb,”
that it knows littl e ab out cha rac ters, fonts, cursor movement, a nd so on. The two sides negoti at e opt io ns t o
determine the capabi lities of the other. For example, a t erminal might su pport full curso r-control char acters.
Once the connection is established, the terminal and host may agree to support the extra characters. This all
happens transparently to the user, who sees only a login screen and none of the negotiation process.
By default, Teln et connects to a pre-set po rt number to access a remote host’s Telnet server. The ETS allows
the specificati on of a port number other tha n the default to be used for the connectio n. For example, if a host
is set up to listen to Telnet requests on port number 1034, that port number can be specified in the Telnet
command entered into the ETS.
Note: The Telnet command is explained in the Command Reference chapter.
Concepts TCP/IP
2-9
2.7.2.2 Rlogin
In addition to Telnet, ETS users can use the Rlogin application to connect to remote TCP/IP hosts. Rlogin
is similar to Telnet, but it can be configured to allow trusted users to log into a host without password
verification. For this reason, Rl ogin can be a s ecurity problem, a nd is not enabl ed on all sit es. TCP/IP Server
Parameters on page 4-5 explains how to set up Rlogin access and di scusses the methods of user verifi cation.
Like the UNIX version of the command, the ETS Rlogin command allows the user to specify a different
username for logging in to remote devic es. Both Telnet a nd Rlogin suppor t the port’s Termtype fiel d, which
allows hosts to discover the type of terminal device automatical ly.
Note: Rlogin is explained in the Command Reference.
TCP/IP implementations generally have no knowledge of remote hosts until a connection is attempted.
There is no searching for a host until the actual connection request is made. The UNIX operating system
supports the rwho faci lity to allo w hosts to see e ach ot her withou t an a ctive co nnecti on, but it i s not always
implemented, enabl ed, or supported. Host s running rwho send out oc casional broadcast s containing the host
name, address, and user informati on. The ETS will listen for rwho broadcas ts and keep track of which UNIX
hosts are available. See Show/Monitor/List [Telnet] Hosts on page 12-113 or your local host
documentation for more information.
2.7.2.3 Subnetworks
TCP/IP Internets are usually broken down into networks, where a host is able to see only the hosts on its
own network or sub-unit. TCP/IP networks then rely on routers (or gateways) to transfer network traffic
to hosts on other networks.
Routers are typically connected to two or more networks, and will pass, or route, TCP/IP messages across
network boundaries. The ETS can be told explicitly which hosts are the gateways for the local network. If
no gateways are currently specified, the ETS will listen to routing protocol packets (for example, RIP) to
decide which hosts are acting as gateways. See Set/Define Server Gateway on page 12-66 for more
information.
The ETS decides at connecti on time whet her th e desir ed TCP/IP host is on the loc al net work segmen t with
the help of the subnet mask on the server. This mask tells how much of the IP address is the network
address, and is applied to the IP addresses of both the ETS and the remote host. If the resulting addresses
are identical, the conne ction is deemed local and the host is contacted directly. I f not, the connection attempt
and all subsequent messages to this host will be directed to the ETS’s gateway host for forwarding. The
subnet mask, if not set expl icitly , will be automati cally con figured f or the given IP address. Se e Set /Define
Server Subnet Mask on page 12-83 for more information.
2.7.3 Name Resolution
TCP/IP hosts generall y have an alphanumeri c host name, such as Phred, in addition t o a numeric IP addr ess,
such as 192.0.1.99. For this reason, the ETS supports the use of a local host table and domain name
servers— hosts that can translate text host names into the numeric addresses that are needed for a
connection.
TCP/IP Concepts
2-10
Text names make it unnecessar y to r emembe r lo ng strings of address numbers . For exampl e, suppose user
Bob wishes to log into a host named “alex.weasel.ctcorp.com.” The other hosts on the network have no
knowledge of which pi ece of hardware is associated wit h this name, so the ET S must translate the name into
a numeric address, such as 199.25.172.6. After the name is translated (or resolved), the connection can be
attempted.
See Set/Define Se rver Domai n on page 12-65 for more information.If the re i s n o local host table or na me
server to provide text name tr anslation, or if the name server(s) can not translate the name, the host’s numer ic
IP address would have to be used for the co nnec ti on. Also, if the ETS has not been told which local ho st is
acting as the name server (see the Set/Define Server Nameserver command), it assumes that none is
available and the connect request will likely fail.
The ETS also allows the s etting o f a default domain name t o be appende d to any hos t name for which name
resolution is performed. In the example above, if Bob’s server had a default domain name of
weasel.ctcorp.com, then Bob could type telnet alex and the ETS would attempt to resolve
alex.weasel.ctcorp.com. This name checking occurs for all ETS commands that require text name
resolution, such as Tel net, Rlogin, and Ping. If the con nect destina tion name ends with a period, the domai n
name is not added to the hostname for resolution.
2.7.4 Local Host Table
The ETS enhances name resolution by providing a simple host table, which is a list of node names and
corresponding IP addresses. Using the Set/ Def ine Telnet Hosts command, the server manager can add
hosts to this table. Thi s allows the user to ente r a text na me desc ribed i n the tabl e in place of an IP addre ss,
which in turn eliminates the need to remember IP addresses. The local host table is especially useful for
sites that do not have a domain name server, or in cases where a few hosts are accessed frequently.
The Show Hosts command displays all curre ntly- known IP node s and how they were learn ed: via the l ocal
host table, a local name server, rwho broadcasts, or name resolution during a connection attempt.
If name serving is enabled, the name server will be asked for the node’s IP address only if the local host
table does not contain the informat io n. This mean s that inc orrec t infor mati on in the loc al host ta ble will be
used, even if it is contrary to what a nameserver might report. The local host table does not have to be
consistent with the name server, but consiste ncy will avoid c onfusion. To mai ntain consi stency, remove the
old hosts from the host table with the Clear/Purge Telnet Hosts command.
Host table aliases should b e easy to type , remember , and re cog nize. Th ey are limit ed to 64 charac ters , with
a maximum length of 16 characters per segment. For example, alex.weasel.ctcorp is legal, while
alex.communicationsserver.ctcorp is not.
The ETS can also get host names and IP add resses from nod e rwho bro adcasts and at tempt t o add entries t o
the host table b ased on thi s infor mation. If the r who addr esses are clea red from t he table, they wi ll reapp ear
the next time the host sends out an r who message. Addres ses will also r eappear if a user attempts to connect
to one of them.
2.7.5 Dynamic Host Control Protocol (DHCP)
DHCP, an extension to BOOTP, allows network administrators to lease IP addresses to network nodes as
needed. ETS servers offer two levels of DHCP support: boot and runtime.
Concepts TCP/IP
2-11
If your ETS has boot mode DHCP support, t he ETS will a ttempt to a cquire an IP address via DHCP at boot
time. If it succeeds, the ETS will save the IP address into NVR and continue with the boot process. Once
running, the ETS’s operational code will attempt to acquire the same IP address from the DHCP server. If
for some reason the runtime DHCP request fails (for example, if there is no response for 15 seconds), the
ETS will use the address saved in NVR.
If your ETS does not support DHCP at the boot level, you can still use DHCP at the operational level. To
enable DHCP in the runtime code, enter the Set/Define Server DHCP Enabled command and reboot the
server.
Note: Enabling DHCP will remove the IP address saved in NVRAM, if there is one.
The ETS will use BOOTP or RARP to acquire an IP address at boot time, and then it will request an IP
address via DHCP once it is running. If the runtime DHCP request fails, the server will use the IP address
stored in NVRAM. If t he DHCP request succeeds, the ETS will use the result ing IP addre ss. It will not save
the IP address to NVRAM or overwrite the saved address (the one acquired by BOOTP or RARP).
If you enter a new IP address with the Set/Define Server IPaddress command, the ETS will assume that
you want to use that address in the future, and will disable DHCP.
Note: When DHCP is used, the IP address saved in NVRAM will change e ach time the
ETS boots, and the List Server Bootparams command (which shows the
characteristics that will be in effect the next time the ETS boots) may show a
different IP address than the one that is currently in use.
TCP/IP Concepts
2-12
2.7.6 Serial Line Internet Protocol (SLIP)
The SLIP protocol allows hosts to communicate via TCP/IP over a serial line instead of Ethernet. Due to
the point-to-point nature of serial lines, only two hosts can communicate over a single line. SLIP is most
frequently used for dialup modem lines, where a SLIP-equipped TCP/IP host can dial into the ETS, begin
a SLIP session, and thus ga in acc ess to the ne twork a ttach ed to t he ETS. The remote host c an sta rt se ssion s
to the ETS or any other hos t on the networ k, subject to security and oth er login res trictions. If multiple TCP /
IP hosts are connected to the ETS via SLIP connections, each SLIP host can also access any of the other
SLIP hosts, with the ETS routing pac kets be tween the serial lines . An example SLIP s etup is s hown below.
Figure 2-4: SLIP Example
Note: See Set/Define SLIP on page 12-95 for more details.
In the example above, assume all host s hav e a subnet mask of 255.255.255.0. All four host s will appear to
be on the same network segment, and all four will be able to start TCP/IP connections with each other.
The ETS in this case “rout es” pac ket s betwe en the seria l lines and the Ether net withou t help from th e ho sts
involved. Note that since all the hosts are on the same network, the ETS is not routing in the true sense of
the word, and any “real” IP routers on the network will not be affected by the SLIP sessions. The ETS is
only directing network traffic to the proper serial port.
The ETS checks each packet it receives to see if it is destined for the ETS, or if it should send it to one of
the SLIP hosts or out to the Ethernet. If an Ethernet packet is sent to the ETS and there is no SLIP connecti on
for it, or if a packet is received from a SLIP port but is not from the host that is supposed to be there, the
packet is discarded. This prevents other hosts from connecting to an active SLIP line and accessing the
ETS’s Ethernet. The ETS also provides ARP replies for its SLIP hosts so that hosts on the Ethernet can
resolve their IP addresses.
There are two restrict ions on ETS SLIP support . First, there can be onl y one host at the end of the serial line.
The ETS will only fo rward packets to and from the host regist ered on the SLIP line, it will not rout e packets
to and from a SLIP network (m ult i ple host s) . Sec ond, a ll of t he hosts connected via seri al li nes mus t be on
the same network and subnet as the server.
ETS
Server
Ethernet Backbone
Modems
Host 192.73.100.11
Host 192.73.100.23
Host 192.73.100.78
Host 192.73.100.172
Serial Lines
AUI Cable
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