System information

Troubleshooting LAN Switching Environments
Book Title
22-454
Figure 22-1 Pin Connections
LAN Switching: Catalyst 1600 Token Ring Port Fails to Open
Symptom: Connections to a Token Ring fail because a Catalyst 1600 Token Ring switch port fails
to open correctly.
Table 22-4 outlines the problems that might cause this symptom and describes solutions to those
problems.
Table 22-4 LAN Switching: Catalyst 1600 Token Ring Port Fails to Open
Incorrect cabling A null-modem cable is needed when attaching a LAN switch directly to terminals or other
stations. A straight-through cable is needed when attaching the switch to a modem. Figure 22-1
illustrates the pin connections to use when you connect the Catalyst 1600 to a terminal using a
null-modem EIA/TIA-232 cable, or to a modem using a straight-through EIA/TIA-232 cable.
Possible
Problem Solution
Incorrect connector Check to make sure that the Token Ring switch port is connected to the correct connector on the
attached device. For detailed information on connector types, refer to the Catalyst 1600 Token
Ring Switch User Guide.
Interface mode
incorrect
Step 1 Make sure that the interface mode of the Token Ring switch port is appropriate for the
attached device. The options are node mode and concentrator mode.
Step 2 Check the port interface mode by reading the port LEDs or LCD panel.
Step 3 You can change the port interface mode using the TrueView Catalyst 1600 Manager or
by connecting a terminal to the serial interface and using the set port ifmode
command.
Command: set port ifmode port mode
Description: Sets the port interface to node or concentrator mode.
Parameters: port Port number mode Port interface (node or concentrator)
For detailed information on interface modes, refer to the Catalyst 1600 Token Ring Switch User
Guide.
Possible
Problem Solution
Catalyst 1600 Terminal
7
2
3
4
5
6
8
20
7
3
2
5
4
20
6
8
Catalyst 1600 Modem
2
3
4
5
6
7
8
20
2
3
4
5
6
7
8
20