I have an issue where communication is present accross a VPLS connection but websites are failing to load which indicates a MTU missmatch / issue. I have tried changing the MTU accross the network to no avail
When testing from one Gateway in Location A pinging a host in Location B. The max size i can ping is 1450.
Our core MPLS links are set Physical MTU 9192 and MPLS MTU 9000
For the CE-Facing interfaces I have not set the MTU so they have defaulted to 1518
The cisco SW MTU has been tested with 1500 aswell as 9000 just for testing purposes but still no luck
Seting the VPLS MTU in the routing instance is also not feasible as this is BGP signalled
You can verify the MPLS core MTU using sweep command
Use sweep command
MX> ping mpls rsvp sweep
On the juniper devices check for incrementing MTU Errors (show interface ge-x/y/z extensive | match "MTU errors")
Above step should help you narrow down the issue in MPLS core and rest of the juniper devices. Try similar commands on cisco devices too.
PS: Please accept my response as solution if it solves your query, kudos are appreciated too!