[c-nsp] VLAN mystery

[Matt Bernstein]

On 15/10/2015 18:36, Joseph Mays wrote:
> Dealing with a mysterious vlan that won't work, right next to an 
> identically configured VLAN on all the same equipment that works fine.
Are you sure on Switch B that both links to Router B are dot1Q? Looks 
like one might be ISL:

> ================================================================================= 
>
> On Switch B
>
> interface FastEthernet0/1
> description to gw1.armplc
> duplex full
> speed 100
> switchport trunk encapsulation dot1q
> switchport mode trunk
> no cdp enable
> !
> interface FastEthernet0/10
> description Hatteras 1 - HN408-U
> switchport trunk encapsulation dot1q
^^^^^^^^^^^^^^^^^^^^^^^^^^
> switchport trunk allowed vlan 1,808,1002-1005
> switchport mode trunk
> no cdp enable
> !
> interface FastEthernet0/17
> description UNUSED
> duplex full
> speed 100

^^^^^ no dot1Q
> switchport trunk allowed vlan 1,888,1002-1005
> switchport mode trunk
> no cdp enable
>

Matt