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looking at 802.1Q frames

Hello!

Just for fun I decided to look at 802.1Q frames between two trunk ports that connect two 3524. What I did is connect the trunk ports via a hub and use Ethereal to watch the traffic.

What I was expecting to see were 0x8100 tagged frames, but just saw standard Etherent tags. Setting the trunk encapsulation to ISL works as expected. This is the configuration for the trunk interface

interface FastEthernet0/24 switchport trunk encapsulation dot1q switchport trunk allowed vlan 1,98,99,1002-1005 switchport mode trunk

My undertanding of non tagged frames was that only the Native VLAN frames are untagged on the trunk.

What am I missing?

TNX

/CM

Reply to
Capitan Mutanda
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i'm so sorry i do not know

Reply to
answer

Were there any active vlans being carried in the trunk? If vlans 98-99 don't exist, they won't be carried will they?

Reply to
jw

Yep. On vlan 99 I put an ftp session of a whole cd image while on vlan

98 there was a continous ping.
Reply to
Capitan Mutanda

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