Cisco SN 5428-2 User Manual
CHA PTER
1
Before Configuring SN 5428-2 Storage Router
Software
The Cisco SN 5428-2 Storage Router installation and configuration tasks consist of the following:
• Install the SN 5428-2 Storage Router according to the Cisco SN 5428-2 Storage Router Hardware
Installation Guide.
• Select how the SN 5428-2 will be deployed: SCSI routing, transparent SCSI routing, or FCIP.
• Configure the SN 5428-2 Storage Router software according to the Cisco SN 5428-2 Storage Router
Software Configuration Guide (this manual).
• Install and configure iSCSI drivers in IP hosts connected to the storage router. The iSCSI driver is
not required for FCIP deployment, or in IP hosts that have a TCP/IP Offload Engine (TOE) with
embedded iSCSI protocol installed.
This chapter is the starting point for SN 5428-2 Storage Router software configuration. It provides some
very basic, abbreviated information as background to help you understand the SN 5428-2 Storage Router
features and the software configuration process. It contains the following topics:
• SN 5428-2 Storage Router Overview, page 1-2
• SCSI Routing Overview, page 1-4
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• Transparent SCSI Routing Overview, page 1-10
• FCIP Overview, page 1-15
• Mixed Mode Overview, page 1-18
• VLAN Access Overview, page 1-20
• Zoning Overview, page 1-21
• Fibre Channel Interface Overview, page 1-23
• Gigabit Ethernet Interface Overview, page 1-23
• Authentication Overview, page 1-24
• SN 5428-2 Cluster Management Overview, page 1-25
• Interface Naming, page 1-25
• Where to Go Next, page 1-26
Cisco SN 5428-2 Storage Router Software Configuration Guide
1-1
SN 5428-2 Storage Router Overview
SN 5428-2 Storage Router Overview
The Cisco SN 5428-2 Storage Router provides universal access to storage over IP networks. The storage
router software controls the operation of the Cisco SN 5428-2 Storage Router. You can configure the
software to provide the following types of access to storage over IP networks:
• SCSI routing only
• Transparent SCSI routing only
• FCIP only
• SCSI routing and FCIP
• Transparent SCSI routing and FCIP
SCSI routing provides IP hosts with access to Fibre Channel (FC) storage devices, using iSCSI protocol.
The iSCSI protocol is an IETF-defined protocol for IP storage (ips).
Note For more information about the iSCSI protocol, refer to the IETF standards for IP storage at
http://www.ietf.org.
Chapter 1 Before Configuring SN 5428-2 Storage Router Software
With SCSI routing, storage device access is managed primarily in the SN 5428-2. (See Figure 1-1.)
Figure 1-1 SCSI Routing
IP hosts
Cisco SN 5428-2
IP
Storage access is managed
in the SN 5428-2.
FC storage devices
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Transparent SCSI routing provides IP hosts with transparent access to intelligent storage arrays using
iSCSI protocol; that is, each IP host is presented as an FC host to an intelligent storage array. With
transparent SCSI routing, availability of storage devices is managed primarily in the intelligent storage
array. (See Figure 1-2.)
Figure 1-2 Transparent SCSI Routing
IP hosts
Cisco SN 5428-2
IP
Intelligent storage
array
FC
1-2
The SN 5428-2
presents each IP host
as an FC host to the
storage array.
Cisco SN 5428-2 Storage Router Software Configuration Guide
Storage access is
managed in the
storage array.
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Chapter 1 Before Configuring SN 5428-2 Storage Router Software
Fibre Channel over IP (FCIP) enables SN 5428-2 Storage Routers to provide connectivity by tunneling
through an IP network between storage area networks (SANs). (See Figure 1-3.)
Figure 1-3 FCIP
SN 5428-2 Storage Router Overview
FC hosts and
storage devices
SAN
SN 5428-2 SN 5428-2
IP
The SN 5428-2s connect
SANs by tunneling though
the IP network
FC hosts and
storage devices
SAN
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In addition to providing services for accessing storage over IP networks, the SN 5428-2 Storage Router
software provides the following services:
• VLAN Access Control—provides IP access control to storage based on a VLAN identifier (VID)
number (in addition to access control through access lists)
• Authentication—provides iSCSI, Enable and Login authentication using AAA authentication
methods
• High Availability (HA)—provides the ability to group storage routers in a cluster for intelligent
failover and other cluster-related functions (for SCSI routing only)
• E_Port with FC Fabric Zoning—provides the ability to connect FC ports to FC switches and
participate in fabric zoning, manage zoning, and support zone mergers
• SNMP/MIB support—provides network management of the SN 5428-2 through SNMP using
selected MIBs
• Gigabit Ethernet Interface features—provides the ability to assign a management IP address per
Gigabit Ethernet interface, multiple IP addresses per SCSI routing instance, and an optional
secondary Gigabit Ethernet interface per IP address used for SCSI routing or SN 5428-2
management. When the SN 5428-2 is deployed for FCIP, provides primary and optional secondary
Gigabit Ethernet interfaces to the FCIP peer.
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• FCIP data compression—enables the SN 5428-2 to dynamically compress FCIP data traffic for
better channel bandwidth utilization
• Buffer credit extension—enables the SN 5428-2 to donate buffer credits from a donor port to
selected FC ports
• Secure Sockets Layer (SSL) support—provides HTTPS connection for secure access through the
web-based GUI
• Secure Shell (SSH) protocol version 2 support—provides high encryption and authentication for
interactive management sessions, and is a common replacement for Telnet
• Routing Information Protocol (RIP) listening support—allows the SN 5428-2 to learn dynamic
routing using RIP (version 1 or version 2) listening
• Service Location Protocol (SLP) support—provides the ability to advertise targets of specified SCSI
routing instances to initiators or servers that use SLP
• Internet Storage Name Service (iSNS) support—provides the ability to register iSCSI targets with
an iSNS server, allowing iSCSI initiators to dynamically discover available storage targets
Cisco SN 5428-2 Storage Router Software Configuration Guide
1-3
SCSI Routing Overview
• LUN Trespass feature—provides a LUN failover feature for selected storage arrays that operate on
the active/passive port model. When enabled, the trespass feature provides a redundant path from
the storage router to the storage array by allowing the storage router to detect a path failure to a
storage array port and perform the necessary operations to fail LUNs over to the other port on the
storage array without using any multi-path software.
• TCP Window Tuning—provides the ability to maximize bandwidth across the network by
automatically setting the local TCP receive window size to the remote TCP receive window size
without user intervention
• A command-line interface (CLI) and a web-based GUI—provides user interfaces for configuration
and maintenance of an SN 5428-2
SCSI Routing Overview
SCSI routing provides IP hosts with access to FC storage devices as if the storage devices were directly
attached to the hosts, with access to devices being managed primarily in the SN 5428-2 Storage Router.
An iSCSI target is an arbitrary name for a group of physical storage devices. The iSCSI targets are
created and mapped to physical storage devices attached to the SN 5428-2. The storage router presents
the iSCSI targets to IP hosts as if the physical storage devices were directly attached to the hosts. (See
Figure 1-4.) With SCSI routing, storage devices are not aware of each IP host; the storage devices are
aware of the SN 5428-2 and respond to it as if it were one FC host.
Chapter 1 Before Configuring SN 5428-2 Storage Router Software
Figure 1-4 SCSI Routing Overview
IP hosts
Cisco SN 5428-2
IP
An IP host accesses a storage
device as if it were directly
attached to the storage device.
FC storage
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To configure an SN 5428-2 Storage Router for SCSI routing, you should have a basic understanding of
the following concepts:
• Routing SCSI Requests and Responses, page 1-5
• Basic Network Structure, page 1-6
• SCSI Routing Mapping and Access Control, page 1-6
• Available Instances of SCSI Routing, page 1-9
Note Along with FC storage, FC host connections and FC switch connections are allowed; however, most of
the illustrations in this manual show only storage connections for the purpose of describing the
SN 5428-2 Storage Router features.
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Chapter 1 Before Configuring SN 5428-2 Storage Router Software
Routing SCSI Requests and Responses
SCSI routing consists of routing SCSI requests and responses between hosts in an IP network and FC
storage. (See Figure 1-5.)
Figure 1-5 Routing SCSI Requests and Responses for SCSI Routing
SCSI Routing Overview
IP hosts
Cisco SN 5428-2
IP
SCSI requests and responses
FC storage
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Each host that requires IP access to storage via an SN 5428-2 Storage Router needs to have a compatible
iSCSI driver installed. Using the iSCSI protocol, the iSCSI driver allows an IP host to transport SCSI
requests and responses over an IP network. From the perspective of a host operating system, the iSCSI
drive appears to be a locally attached SCSI or Fibre Channel drive to the host.
SCSI routing consists of the following main actions (See Figure 1-6):
• Transporting SCSI requests and responses over an IP network between the hosts and the SN 5428-2
Storage Router
• Routing SCSI requests and responses between hosts on an IP network and FC storage
• Transporting SCSI requests and responses between the SN 5428-2 Storage Router and FC storage
Figure 1-6 SCSI Routing Actions
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IP hosts
Transporting SCSI
requests and responses
over an IP network
Cisco SN 5428-2
IP
Routing SCSI requests
and responses
Transporting SCSI
requests and responses
between an SN 5428-2
FC storage
and storage
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1-5
SCSI Routing Overview
Basic Network Structure
Figure 1-7 shows the basic structure of a SCSI routing network. IP hosts with iSCSI drivers access the
storage routers through an IP network connected to the Gigabit Ethernet interface of each storage router.
The storage routers access storage devices connected to the Fibre Channel interfaces of each storage
router. A management station manages the storage routers through an IP network connected to the
management interface of each storage router. For high availability (HA) operation, the storage routers
communicate with each other over two networks: the HA network connected to the HA interface of each
storage router and the management network connected to the management interface of each storage
router.
Figure 1-7 SCSI Routing Basic Network Structure
Chapter 1 Before Configuring SN 5428-2 Storage Router Software
Cisco SN 5428-2
Contains SN 5428-2
software
IP host
IP host
Contains iSCSI
driver
IP
Contains iSCSI
driver
HA
Management
Cisco SN 5428-2
SCSI Routing Mapping and Access Control
SCSI routing occurs in the SN 5428-2 Storage Router through the mapping of physical storage devices
to iSCSI targets. An iSCSI target is an arbitrary name for a group of physical storage devices. You can
map an iSCSI target to multiple physical devices. An iSCSI target always contains at least one Logical
Unit Number (LUN). Each LUN on an iSCSI target is mapped to a single LUN on a physical storage
target.
You can choose either of two types of storage mapping: target-and-LUN mapping or target-only
mapping. Target-and-LUN mapping maps an iSCSI target and LUN combination to a physical storage
target and LUN combination. Target-only mapping maps an iSCSI target to a physical storage target and
its LUNs.
With target-and-LUN mapping, an iSCSI target name and iSCSI LUN number are specified and mapped
to the physical storage address of one LUN; either a WWPN + LUN (World Wide Port Name + LUN)
combination, a LUN ID (unique LUN identifier), or a LUN serial number.
FC storage
Management
station
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Chapter 1 Before Configuring SN 5428-2 Storage Router Software
If the LUN is available, it is made available as an iSCSI LUN and numbered with the iSCSI LUN number
specified. For example, if an iSCSI target and iSCSI LUN specified as Database, LUN 9 were mapped
to the physical storage address, WWPN 3100112233445566, LUN 12, then LUN 12 would be available
as one iSCSI LUN. An iSCSI driver would see the iSCSI target named Database, with one iSCSI LUN
identified as LUN 9. The iSCSI LUN would appear as one storage device to a host. (See Table 1-1.)
Table 1-1 Target-and-LUN Mapping Example
SCSI Routing Overview
Apparent to Host as
Local Disk
Local Disk (D:) Database LUN 9 WWPN
iSCSI Target
Name
iSCSI LUN
Available
Physical Storage
Address
Physical LUN
Available
LUN 12
3100112233445566
Apparent as one
locally attached
storage device.
Database
appears as one
controller with
one LUN
available.
iSCSI LUN is
numbered as
specified and
can be different
than the
Specifies the storage
address of a storage
controller.
The LUN number
is specified as the
only LUN to be
mapped.
physical LUN
number.
With target-only mapping, an iSCSI target name is specified and mapped to the physical storage address
of a storage controller only; a WWPN. Any LUNs that are available in the storage controller are made
available as iSCSI LUNs and are numbered the same as the LUNs in the storage controller. For example,
if an iSCSI target specified as Webserver2000 were mapped to the physical storage address WWPN
3100112233445577, and LUNs 0 through 2 were available in that controller, those LUNs would become
available as three iSCSI LUNs. An iSCSI driver would see the iSCSI target named Webserver2000 as a
controller with three iSCSI LUNs identified as LUN 0, LUN 1, and LUN 2. Each iSCSI LUN would
appear as a separate storage device to a host. (See Tabl e 1-2 .)
Table 1-2 Target-only Mapping Example
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Apparent to Host as
Local Disk
iSCSI Target
Name
iSCSI LUNs
Available
Physical Storage
Address
Local Disk (D:) Webserver2000 LUN 0 WWPN
3100112233445577
Local Disk (E:) Webserver2000 LUN 1 WWPN
3100112233445577
Local Disk (F:) Webserver2000 LUN 2 WWPN
3100112233445577
Apparent as three
locally attached
storage devices.
Webs er ve r2 00 0
appears as one
controller with
LUNs 0, 1, and
iSCSI LUNs
are numbered
the same as
physical LUNs.
Specifies the storage
address of a storage
controller.
2 available.
Cisco SN 5428-2 Storage Router Software Configuration Guide
Physical LUNs
Available
LUN 0
LUN 1
LUN 2
LUNs 0, 1, and 2
are available for
mapping.
1-7
SCSI Routing Overview
Chapter 1 Before Configuring SN 5428-2 Storage Router Software
Access for SCSI routing is controlled in the IP hosts and the storage router. In an IP host, the iSCSI driver
is configured with the Gigabit Ethernet IP address of the SCSI routing instance in the storage router with
which the host is to transport SCSI requests and responses. In a storage router, access is controlled
through an access list and a VLAN identifier (VID) number of the hosts. Additionally, access can be
further controlled in the SN 5428-2 through authentication. See the “Authentication Overview” section
on page 1-24 for more information about authentication.
An access list enables access to storage devices attached to the SN 5428-2 according to any combination
of host IP address(es), CHAP user name(s), or iSCSI name(s). An access list contains these combinations
of hosts allowed to access the storage devices. Host VID enables access to storage devices according to
the VID of each host. See the “VLAN Access Overview” section on page 1-20 for more information
about VLAN access.
For each iSCSI target, you can associate one access list allowing read/write access, and one access list
allowing read-only access. See Chapter 6, “Configuring SCSI Routing,” for more information about
read/write and read-only access.
You can use a combination of access lists and VIDs to configure access in the SN 5428-2; that is, you
can specify that certain hosts according to IP address in a VLAN can access storage devices attached to
the SN 5428-2.
Once the access is configured in the hosts and the SN 5428-2, and once the storage mapping is
configured in the SN 5428-2, the SN 5428-2 routes SCSI requests and responses between hosts and the
mapped storage devices.
Figure 1-8 represents the concept of storage mapping and access control for SCSI routing. In the figure,
the SN 5428-2 Storage Router provides three IP hosts with IP access to disk drives across four disk
controllers. The SN 5428-2 contains two SCSI routing instances: one configured with IP address
10.1.2.3 for the Gigabit Ethernet interface and the other with IP address 10.1.2.4. The iSCSI drivers in
each IP host are configured to access those SCSI routing instances by their IP addresses through the
Gigabit Ethernet interface. An access list in the storage router or VID (or both) specifies that hosts A,
B, and C are allowed to access the mapped storage devices. From the perspective of a host, each disk
drive mapped to it appears as a locally attached disk drive. Table 1-3 shows the correlation between an
access list and/or VID, the Gigabit Ethernet IP addresses of the SCSI routing instances, and the storage
device mapping.
Note The purpose of Figure 1-8 and Table 1-3 is only to illustrate the concept of storage mapping and access
control. The IP addresses will vary according to each site. Similarly, the type of storage addressing (for
example, LUN ID, WWPN + LUN or LUN serial number) will vary according to the types of storage
and the types of storage addressing preferred at each site. In addition, the figure and the table exclude
any additional SN 5428-2 Storage Routers that could be configured for high availability.
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Figure 1-8 SCSI Routing Storage Mapping and Access Control Concept
SCSI Routing Overview
IP host A
IP host B
IP
Controller 1
IP host C
Storage
accessible by
IP host A
Table 1-3 SCSI Routing Storage Mapping and Access Control Concept
Cisco SN 5428-2
with IP addresses
10.1.2.3 and 10.1.2.4
123
123
Controller 2
123
Storage
accessible by
IP host C
Controller 4
123
Controller 3
Storage
accessible by
IP host B
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Hosts Allowed
Access via SN 5428-2
Access List and/or
VID
Storage Devices Apparent
to Host as Locally
Attached Devices
Via GbE IP
Addresses of SCSI
Routing Instances
Mapped To
Controller
Host A Local Disk (D:) 10.1.2.3 1 1
Local Disk (E:) 10.1.2.3 1 2
Local Disk (F:) 10.1.2.3 1 3
Local Disk (G:) 10.1.2.3 2 1
Local Disk (H:) 10.1.2.3 2 2
Local Disk (I:) 10.1.2.3 2 3
Host B Local Disk (D:) 10.1.2.3 3 1
Local Disk (E:) 10.1.2.3 3 2
Host C Local Disk (D:) 10.1.2.4 4 1
Local Disk (E:) 10.1.2.4 4 2
Local Disk (F:) 10.1.2.4 4 3
Local Disk (G:) 10.1.2.4 3 3
Mapped To
Drive
Available Instances of SCSI Routing
You can configure an SN 5428-2 Storage Router with up to 12 instances of SCSI routing services. Each
instance needs to be configured with the following:
• One or more unique IP addresses assigned to either one or both Gigabit Ethernet interfaces
• Mapping between iSCSI target names and physical storage addresses
• Access control
When an SN 5428-2 is part of a cluster, an instance of SCSI routing can run on only one storage router
in a cluster at any given time. See the “SN 5428-2 Cluster Management Overview” section on page 1-25
for more information about storage router clusters.
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