[c-nsp] Turning on MPLS.

[Alex A. Pavlenko]

Colleagues.

Consider the following network setup
 
[internet]  -  [c7301] - [cat3560G] - [cat3750] - [c7200] - [cat3550] - [customers]

Catalyst switches work as l2 and routers are "router on a stick".  
I've tried to turn on MPLS between routers. The result config for c7200 follows

mpls label protocol ldp
mpls ldp advertise-labels
int f0/0.96
 ip address x.x.x.1 255.255.255.252
 mpls ip

Most works fine, but some customers began to complain that they can not access
certain sites in the Internet. I'm not sure but the situation looks like there is MTU mismatch
somewhere.  Is it mandatory to check and adjust MTUs when turning on MPLS? 
No idea where to look else, please help.
Thanks.

--
Alex Pavlenko
System Administrator
Sandy Info