Symptom
A 9500X configured for StackWise Virtual may show link down despite the remote link showing as up.
Output of show interfaces may show link down, line protocol down.
For example:
9500X#show interfaces hundredGigE 2/0/9
HundredGigE2/0/9 is down, line protocol is down (notconnect)
Link is being used for an SVL link and the the SVL is up:
9500X#show stackwise-virtual link
Stackwise Virtual Link(SVL) Information:
----------------------------------------
Flags:
------
Link Status
-----------
U-Up D-Down
Protocol Status
---------------
s-Suspended P-Bundled E-Error D-Down R-RLayer3 I-Indiv
------------------------------------------------------
Switch SVL Ports Link-Status Protocol-Status
------ --- ----- ----------- ---------------
1 1 HundredGigE1/0/9 U P
HundredGigE1/0/35 U P
2 1 HundredGigE2/0/9 U P
HundredGigE2/0/35 U P
Despite the link showing down in the output of show interfaces, the issue appears to be cosmetic because the SVL link continues to forward traffic.
Conditions
This has been seen on a 9500X running 17.12.02 configured in StackWise Virtual.
Workaround
A failover via "redundancy force-switchover" results in the links showing up post reload.
