Cisco Catalyst 3750-X

5-33
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 5 Managing Switch Stacks
Troubleshooting Stacks
Switch#/ Stack Neighbor Cable Link Link Sync # In
Port# Port Length OK Active OK Changes Loopback
Status To LinkOK
-------- ------ -------- -------- ---- ------ ---- --------- --------
1/1 OK 2 50 cm Yes Yes Yes 1 No
1/2 Absent None No cable No No No 2 No
2/1 Down None 50 cm No No No 2 No
2/2 OK 1 50 cm Yes Yes Yes 1 No
Only one end of the cable connects to a stack port, Port 1 on Switch 2.
• The Stack Port Status value for Port 2 on Switch 1 is Absent, and the value for Port 1 on Switch 2 is
Down.
• The Cable Length value is No cable.
Diagnosing the problem:
• Verify the cable connection for Port 2 on Switch 1.
• Port 2 on Switch 1 has a port or cable problem if
– The In Loopback value is Yes.
or
– The Link OK, Link Active, or Sync OK value is No.
Fixing a Bad Connection Between Stack Ports
Stack cables connect all members. Port 2 on Switch 1 connects to Port 1 on Switch 2.
This is the port status:
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 2 50 cm Yes Yes Yes 1 No
1/2 Down None 50 cm No No No 2 No
2/1 Down None 50 cm No No No 2 No
2/2 OK 1 50 cm Yes Yes Yes 1 No
Diagnosing the problem:
• The Stack Port Status value is Down.
• Link OK, Link Active, and Sync OK values are No.
• The Cable Length value is 50 cm. The switch detects and correctly identifies the cable.
The connection between Port 2 on Switch 1 and Port 1 on Switch 2 is unreliable on at least one of the
connec
tor pins.