TRUNKING 802.1Q and NAT (2621 / switch)

[luisbeu]

My problem:

I need to trunk, a Cisco 2621 router with another Enterasys switch...using one physical interface fast ethernet ==> trunking 802.1q ===> dot1q ===> sub interfaces ==> objetive: to prove internet access per VLAN (using 2621 wan connection: frame-relay / "DLCI per VLAN traffic&quot

In Enterasys switch, each VLAN has IP plan, and in some cases, we have the same IP plan for different VLANs.

PROBLEM: When I configure the sub interfaces fast ethernet in 2621, we received the message: Overlaping networks (when ip from this sub interfaces has the same subnet).

I think I need to use a NAT scheme, to translate the ip from sub interface fast ethernet (property from VLANx) to valid ip address, and the route this one to the respective wan frame-relay DLCI.

PLEASE, HELP ME....


tks...luisbeu / BRAZIL

 

[gaveeve]

I don't think you can do this. How is the router to differentiate between the different subinterfaces? They have the same physical and logical characteristics. Each VLAN needs its own ip subnet. Nat doesn't help because the router won't know which subinterface to Nat as the ip is the same.

 

[luisbeu]

Gaveeve,

Thanks a lot!!!

Do you have any suggestion to solve my problem?
Do you know some case with this kind o problem?

The option for change the IP address is some VLAN is not good.

In my situation, inter VLAN routing is a problem too.


Thanks my friend

[]s