07-15-2008 12:10 PM - edited 03-06-2019 12:12 AM
We have a Cisco 3640 and Catalyst 3500's adn are using ISL encap for our Trunking Encapsulation. I want to change our encapsulation from ISL to 801.2Q and want to know the steps to complete this. Can I simply change the encapsulation type on the switches and the router or must I recreate all the VLAN's from scratch with the new 802.1Q
07-15-2008 12:15 PM
This should just be as easy as changing the encapsulation from isl to dot1q.
3550
switchport trunk encapsulation dot1q
3640
encapsulation dot1q (vlan#)
Mark
07-15-2008 12:56 PM
Mark
Thanks for your quick response, I suspected this was what was needed but wanted to be sure
07-15-2008 12:40 PM
Hello Chris,
you just need to change the trunk encapsulation protocol on the switch side and router subif configuration (encapsulation command)
Be aware that on the router side you need to go under each subif and use the command encapsulation dot1q
You need to do this for all subifs. If you don't do for one your subif that subif will be isolated.
You can check you are receiving and sending frames on vlans of interest with show vlan on the router shell.
Hope to help
Giuseppe
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