Black Box 16 port User Manual
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•if your network is congested, subnet it with a bridge; however, bear in mind the recommendations in the previous paragraph.

Host problems

Cannot access a host by name

•if using DNS or if DNS is required, ensure a nameserver is configured on your unit and is accessible (ping it).

•if not using DNS, ensure the host is configured in the host table. Check access to the host by pinging it using the host’s IP address.

Cannot access a host on a local network


•the network address is correct.

•the subnet mask is set correctly and reflects the network configuration.

•the broadcast address is set correctly and reflects the network configuration.

Cannot access a host on a remote network

•use the show route command to verify that there is a route to the remote host. If no gateway is specified, ensure a default gateway is specified. Ping the default gateway to check if it is working.

•Consider the situation beyond the gateway; e.g. are intermediate gateways and the remote host available? Also, check the messages returned by the show route command; e.g. that a particular host or gateway is unreachable.

Gateways added into the gateway table are ignored by the unit

•have you used BOOTP and entered a single static gateway in the bootptab file entry? If yes, the other gateways will be ignored. See Appendix F BOOTP for more information

Black Box Console Server user guide


Access to host lost after a few minutes

•If the route to this host goes through routers, make sure those routers are all sending RIP packets across the networks.

You see a message saying your host is in use.

•delete your host as either, a DNS or WINS host, or a gateway, then retry the ‘delete host’ command/menu item. You may have configured your host as a DNS or WINS host, or a gateway.

The connection fails when the user ‘ip_host’ parameter is set to

other factors: several hosts are entered in the unit’s host table

•check the host ip address entered in the server configuration; it is this ip address - and not hosts in the host table - which the unit will use when a user’s ip_host is set to

JETset problems

Trying to access JETSET you see an ‘alert’ dialog box, e.g. :

•change the parameter ‘gui_access’ to ‘on’.

Black Box Console Server user guide


Login problems

User is waiting up to 60 seconds before login is accepted or denied

other factors: authentication is set to ‘both’ or ‘RADIUS’. User has entered username and password, and has pressed <return> key.

check RADIUS configuration of primary and secondary authentication/accounting hosts specified, and you have retry and timeout values greater than the default, the unit will be spending time trying each of these hosts and keeping the user waiting.

adjust RADIUS configuration: specify just one host, reduce timeout and retry values to the default or less than default.

when connecting using a reverse ssh connection, a delay of about 10 seconds for SSH version 1 will be experience. A delay of 20 seconds for SSH version 2 will be experienced. These delays are due to the negotiation of a secure LAN connection. This involves the exchanging of encryption messages to establish a secure communication.

You cannot progress beyond the ‘login’ and ‘password’ prompts (when authentication is set to either ‘both’ or ‘RADIUS’)

check the setting of ‘account_authenticator’ flag is the same in the unit and the RADIUS host; either they should both check or both ignore the authenticator field. If you are not sure, change the setting in the unit; see if this fixes the problem.

on the RADIUS host check the secret (password); you should see it displayed in clear text in the RADIUS clients file. If you are unsure whether it is the same secret which you entered in the unit, go to the unit and re-entera new secret.

on the RADIUS host check there is only one entry for a particular user; do not have multiple entries of the same username (although passwords may be different).

You cannot obtain a login on any of thefront-mountedports

Connect via the Admin port and check the settings of the front-mountedports; they have probably been set to ‘direct’ or ‘silent’ telnet/rlogin.

Black Box Console Server user guide


You have lost or don't know your password (as ‘admin’ user)

you must reset the unit to its factory default settings using the ‘reset’ switch on the rear panel. There is no procedure to access the unit without a password.

at the remote end the client software locks up

other factors: security (CHAP) is enabled on the line.

disable CHAP re-challengeparameter (challenge_interval) in the unit. Some PPP client software does not work when receiving CHAPre-challenges.

Black Box Console Server user guide