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3850 doesn't show a trunked port as such; instead shows it as basic port in vlan 1.

suelange
Level 1
Level 1

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

1 Accepted Solution

Accepted Solutions

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.

View solution in original post

5 Replies 5

Predrag Jovic
Level 3
Level 3

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.

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!! :-)

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.

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!

You're welcome.

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