System information

Troubleshooting IBM
Book Title
10-228
Possible Problem Solution
Media problem Verify the line using the show interfaces exec command. If the interface or line
protocol is down, troubleshoot the media. For LAN media, refer to the chapter that
covers your media type.
Ethernet–to–Token
Ring address mapping
is misconfigured
Step 1 Use the show bridge exec command to verify the existence of the
Ethernet station.
Ethernet and Token Ring addresses use opposite bit ordering schemes.
The Token Ring address 0110.2222.3333 is equivalent to the Ethernet
address 8008.4444.cccc.
Ethernet–to–Token
Ring address mapping
is misconfigured
Step 2 Use the show spanning exec command to determine whether the
Ethernet port is in forwarding mode.
Example:
The following is sample output from the show span command:
RouterA> show span
Bridge Group 1 is executing the IBM compatible spanning
tree protocol
Bridge Identifier has priority 32768, address
0000.0c0c.f68b
Configured hello time 2, max age 6, forward delay 4
Current root has priority 32768, address
0000.0c0c.f573
Root port is 001A (TokenRing0/0), cost of root path is
16
Topology change flag not set, detected flag not set
Times: hold 1, topology change 30, notification 30
hello 2, max age 6, forward delay 4, aging 300
Timers: hello 0, topology change 0, notification 0
Port 001A (TokenRing0/0) of bridge group 1 is
forwarding. Path cost 16
Designated root has priority 32768, address
0000.0c0c.f573
Designated bridge has priority 32768, address
0000.0c0c.f573
Designated port is 001B, path cost 0, peer 0
Timers: message age 1, forward delay 0, hold 0
Port 002A (TokenRing0/1) of bridge group 1 is blocking.
Path cost 16
Designated root has priority 32768, address
0000.0c0c.f573
Designated bridge has priority 32768, address
0000.0c0c.f573
Designated port is 002B, path cost 0, peer 0
Timers: message age 0, forward delay 0, hold 0
Port 064A (spanRSRB) of bridge group 1 is disabled.
Path cost 250
Designated root has priority 32768, address
0000.0c0c.f573
Designated bridge has priority 32768, address
0000.0c0c.f68b
Designated port is 064A, path cost 16, peer 0
Timers: message age 0, forward delay 0, hold 0
A port (spanRSRB) is created with each virtual ring group. The port is
disabled until one or more peers go into open state in the ring group.