BCMSN: sh int fa# switchport -> operational mode?

mzinzmzinz Member Posts: 328
Hi all,

I've begun studying for my BCMSN and ran into something odd today. I have two switches set up, both are set to dynamic desirable.

When running sh int fa0/16 switchport, I get the following output:
XX-C2950_A#sh int fa0/16 swit
Name: Fa0/16
Switchport: Enabled
Administrative Mode: dynamic desirable
Operational Mode: static access
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: native
<snip>

There is only one VLAN on this network, so is it not trunking because trunking wouldn't be necessary? It seems to me that if both sides are dynamic desirable, it would automatically establish a trunk...

Why is it operational mode: static access??
_______LAB________
2x 2950
2x 3550
2x 2650XM
2x 3640
1x 2801

Comments

  • cisco_troopercisco_trooper Too many Member Posts: 1,442 ■■■■□□□□□□
    What does the far end interface look like?....

    Do you have this interface in access mode?

    Show us the interface configs...
  • mzinzmzinz Member Posts: 328
    What does the far end interface look like?....

    Do you have this interface in access mode?

    Show us the interface configs...

    I realized what the issue was.

    I had mixed up my CDP ports and was looking at the switchport connected to a router. After looking at a switchport connected to a switch, I did notice that OP Mode was indeed "trunk".

    Here's a new question: If I configure the router with subinterfaces and encap dot1q, will the switch change from OPMode access to OPMode trunk? I'm assuming yes.
    _______LAB________
    2x 2950
    2x 3550
    2x 2650XM
    2x 3640
    1x 2801
  • kalebkspkalebksp Member Posts: 1,033 ■■■■■□□□□□
    mzinz wrote: »
    If I configure the router with subinterfaces and encap dot1q, will the switch change from OPMode access to OPMode trunk? I'm assuming yes.

    I doubt that routers send DTP packets, so they wouldn't negotiate a trunk. I'd lab it up to double check.
  • cisco_troopercisco_trooper Too many Member Posts: 1,442 ■■■■□□□□□□
    kalebksp wrote: »
    I doubt that routers send DTP packets, so they wouldn't negotiate a trunk. I'd lab it up to double check.

    I concur...
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