We have recently had a QinQ link provisioned, but have noticed mtu issues when testing.
The link is terminated on 2950's(Trunk Ports) at each end, with the 2950's then connected(Also trunk ports) to 7204VXRs, and the various vlans broken out into dot1q Ints.
Without MPLS(Including MPLS L3 VPNs) running on the link, we can access all WebSites without issue - As soon as MPLS is enabled, some sites are not accessible(https sites, www.smh.com.au...)
If we switch back to our primary link(ATM), we also do not experience any mtu issues.
I came across the following link: http://www.cisco.com/warp/public/473/175.html - Is increasing the system mtu something we must do?
Thanks in advance.