Dell POWEREDGE M1000E - Manual (Page 172)

6-30
Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
OL-13270-03
Chapter 6 Managing Switch Stacks
Troubleshooting Stacks
Identifying Loopback Problems
• Software Loopback, page 6-30
• Software Loopback Example: No Connected Stack Cable, page 6-31
• Software Loopback Examples: Connected Stack Cables, page 6-31
• Hardware Loopback, page 6-32
• Hardware Loopback Example: LINK OK event, page 6-32
• Hardware Loop Example: LINK NOT OK Event, page 6-32
Software Loopback
In a stack with three members, stack cables connect all the members.
Switch# show switch stack-ports summary
Switch#/ Stack Neighbor Cable Link Link Sync # In
Port# Port Length OK Active OK Changes Loopback
Status To LinkOK
-------- ------ -------- -------- ---- ------ ---- --------- --------
1/1 OK 3 50 cm Yes Yes Yes 1 No
1/2 OK 2 3 m Yes Yes Yes 1 No
2/1 OK 1 3 m Yes Yes Yes 1 No
2/2 OK 3 50 cm Yes Yes Yes 1 No
3/1 OK 2 50 cm Yes Yes Yes 1 No
3/2 OK 1 50 cm Yes Yes Yes 1 No
If you disconnect the stack cable from Port 1 on Switch 1, these messages appear:
01:09:55: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 3 has changed to state DOWN
01:09:56: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 1 Switch 1 has changed to state DOWN
Switch# show switch stack-ports summary
Switch#/ Stack Neighbor Cable Link Link Sync # In
Port# Port Length OK Active OK Changes Loopback
Status To LinkOK
-------- ------ -------- -------- ---- ------ ---- --------- --------
1/1 Absent None No cable No No No 1 No
1/2 OK 2 3 m Yes Yes Yes 1 No
2/1 OK 1 3 m Yes Yes Yes 1 No
2/2 OK 3 50 cm Yes Yes Yes 1 No
3/1 OK 2 50 cm Yes Yes Yes 1 No
3/2 Down None 50 cm No No No 1 No
If you disconnect the stack cable from Port 2 on Switch 1, the stack splits.
Switch 2 and Switch 3 are now in a two-member stack connected through stack cables.
Switch# show sw stack-ports summary
Switch#/ Stack Neighbor Cable Link Link Sync # In
Port# Port Length OK Active OK Changes Loopback
Status To LinkOK
-------- ------ -------- -------- ---- ------ ---- --------- --------
2/1 Down None 3 m No No No 1 No
2/2 OK 3 50 cm Yes Yes Yes 1 No
3/1 OK 2 50 cm Yes Yes Yes 1 No
3/2 Down None 50 cm No No No 1 No