Confused about output of show vlan id command

[red red]

I  configured a few vlans on a switch. 3 vlans, each assigned only one port. The ouput of show vlan brief shows me exactly what I would expect:

IOU1#show vlan bri

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Et0/0, Et0/3, Et1/3
101  VLAN0101                         active    Et1/0
102  VLAN0102                         active    Et1/1
103  VLAN0103                         active    Et1/2
1002 fddi-default                     act/unsup
1003 token-ring-default               act/unsup
1004 fddinet-default                  act/unsup
1005 trnet-default                    act/unsup

But confusingly when I do a show vlan id for one of my vlans it lists the vlan's interface and then two other interfaces:

IOU1#show vlan id 102

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
102  VLAN0102                         active    Et0/1, Et0/2, Et1/1

VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
102  enet  100102     1500  -      -      -        -    -        0      0

Primary Secondary Type              Ports
------- --------- ----------------- ------------------------------------------

Et0/1 and Et0/2 are trunks to two other switches. I don't get why its listing those trunk ports though I was only expecting it to show Et1/1. Is listing those ports there because this vlan is connected via trunk ports to other switches? I don't know exactly what those two interfaces there is telling me.

[Bilal Nawaz]

I think that the linux/unix versions of IOS, and we can usually include NXOS with this behaviour, shows every trunk and access port (in the case of NXOS port-channel and also members of port-channels too) carrying the vlan.

I'm not entirely sure why there's a change, but thats the way it is.

[red red]

So this is just IOU/IOL behavior?

If this was a real switch, in this example, I would only see Et1/1 correct?

[Bilal Nawaz · Accepted solution]

I think IOU and IOL behave this way. When you say real switch, on nexus platforms in my experience they are same as what you have shown above as IOU.

A switch like C3750, C3560, C3650, C3850 etc.... they will have regular output that you might be used to, i.e. not showing trunk interfaces in the vlan id output.

Hope this helps.