04-05-2009 10:56 AM - edited 03-06-2019 05:00 AM
Say you have this config (found on internet browsing)...
interface FastEthernet0/19
description AP1120G-Gnd
switchport access vlan 50
switchport trunk encapsulation dot1q
switchport trunk native vlan 50
switchport trunk allowed vlan 50,51
switchport mode trunk
switchport nonegotiate
!
How can this work, having an access port and trunk on same port? A trunk port will allow all VLAN, but this is pruned to only let VLANs 50 and 51 through, but then why the sw ac vl 50 cmd?
Again, this is just someones config I found on internet, so it might be incorrect.
Thx again
04-05-2009 11:07 AM
I can fully understand why you are confused. One normally configures a port to be an access port or a trunk port. This is configured as both.
The reason that this is done is to have a deterministic failure scenario in the event that the port stops trunking. If the port ceases to trunk properly, it will automatically place itself in vlan 1. This configuration is meant to force into vlan 50 instead.
HTH
Victor
04-05-2009 11:10 AM
Thanks for the explanation, I got the original page from here:
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