[c-nsp] MTU - issue while doing VPLS over VPLS!

[sthaug at nethelp.no]

> we are deploying Cisco metro Switch to create VPLS network as below.
> 
> PC-----Cisco Switch + Cisco switch ------------E1 Link [ service provider]
> ---------Cisco Switch + Cisco Switch -----internet 
> 
> For E1 link , we are using protocol converter that its Ethernet port only
> support MTU 1500. That means we have MTU 1500 for backhaul link.
> 
> Now when we do VPLS or  VPLS over VPLS ,  There are some application not
> working properly. 

This is expected.

> I want to know ,  does Cisco Switch fragment the packet at its outer
> interface of the switch that is connect to E1 link.

No, why should it? You're doing VPLS which is an L2 technology.

> Or shall we ask Service
> provider to increase the MTU [ or place protocol converter that support
> higher MTU]

If you want 1500 bytes plus VPLS, you need a higher MTU through your
protocol converters *and* the E1 service provider link.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no