How to perform loopback test to identify faulty port on switch ISL?
Applies to
- CN1610 cluster network switches.
- Hardware issue on an ISL port.
Description
- One of the ISL links flaps or goes down on both the cluster interconnect switches.
(CN1610switch1) #show port 0/15,0/16
Admin Physical Physical Link Link LACP Actor
Intf Type Mode Mode Status Status Trap Mode Timeout
--------- ------ --------- ---------- ---------- ------ ------- ------ --------
0/15 PC Mbr Enable 10G Full 10G Full Up Enable Enable long
0/16 PC Mbr Enable 10G Full Down Enable Enable long
(CN1610switch2) #show port 0/15,0/16
Admin Physical Physical Link Link LACP Actor
Intf Type Mode Mode Status Status Trap Mode Timeout
--------- ------ --------- ---------- ---------- ------ ------- ------ --------
0/15 PC Mbr Enable 10G Full 10G Full Up Enable Enable long
0/16 PC Mbr Enable 10G Full Down Enable Enable long
- It can not be determined just by physical inspection or log analysis on which switch the issue lies.
- A loopback test can be used to investigate whether it is caused by a faulty cable or an SFP on the ISL port of a particular switch.