09-08-2017 06:13 AM - edited 03-08-2019 11:57 AM
replacing 3750's wih 3850s. Previously had 4 ports in a port channel that formed a trunked uplink. I also had a port that lead to a VM server which we treated as a trunked port so it could carry various vlans. In duplicating that set up on the 3850's, "show int status" doesn't list the port-channel or it's members as a trunk even though the configuration is present. On the server trunk, it does show as a trunk. I can't figure out why one and not the other? None of the ports in question currently have anything connected (I'm still building this switch for a replacement to be done next week), but one link shows trunked and the other two do not. The only other difference I can find is that I have set specific vlans to be carried on one trunk link, while the other (by default) should carry all vlans. From the 3850:
RACK-A3#show int status
Port Name Status Vlan Duplex Speed Type
Te1/1/3 Link to SHB-7K1 notconnect 1 full auto SFP-10GBase-SR
Te1/1/4 Link to SHB-7K1 notconnect 1 full auto SFP-10GBase-SR
Gi2/0/10 VM02 APDV notconnect trunk auto auto 10/100/1000BaseTX
The ten gig port(s) show they are not a trunk. However the configs show they are supposed to be:
interface TenGigabitEthernet1/1/3
description Link to SHB-7K1
switchport mode trunk
channel-group 48 mode passive
end
!
interface TenGigabitEthernet1/1/4
description Link to SHB-7K1
switchport mode trunk
channel-group 48 mode passive
end
interface GigabitEthernet2/0/10
description VM02 APDV
switchport trunk allowed vlan 1,41-43
switchport mode trunk
switchport nonegotiate
no snmp trap link-status
spanning-tree portfast disable
spanning-tree bpduguard disable
spanning-tree link-type point-to-point
end
Even the channel port that the two Ten Gig uplinks belong to is defined as a trunk, but shows in the status output that it is not…
interface Port-channel48
switchport mode trunk
end
Po48 notconnect unassigned auto auto
Solved! Go to Solution.
09-08-2017 06:59 AM - edited 09-08-2017 07:06 AM
Don't know, there is no output here for that one (except maybe - the reason is command switchport nonegotiate, so does not need to negotiate trunk - it is always trunk :) ).
I all the time have that situation. Ports are always listed as ports in VLAN 1 untill those are listed as connected - then those ports are not present in output from sh vlan brief, buut are present in sh int trunk.
09-08-2017 06:45 AM - edited 09-08-2017 06:46 AM
When interface changed status to "connected" it will be removed from VLAN list and it will be listed as output when
sh int trunk
is issued.
09-08-2017 06:56 AM
okay, I can buy that. Except that, how come port 2/0/10, which is also not connected and a trunk, shows as a trunk? inquiring minds are just too curious!! :-)
09-08-2017 06:59 AM - edited 09-08-2017 07:06 AM
Don't know, there is no output here for that one (except maybe - the reason is command switchport nonegotiate, so does not need to negotiate trunk - it is always trunk :) ).
I all the time have that situation. Ports are always listed as ports in VLAN 1 untill those are listed as connected - then those ports are not present in output from sh vlan brief, buut are present in sh int trunk.
09-08-2017 07:05 AM
perfect, thank you so much for the reassurance! We have limited down time to put 14 of these beggers on line and I don't want to have anything unexpected jump up and bite us in the middle of the process!
09-08-2017 07:10 AM
You're welcome.
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