Hello-
I have a mikrotik box at the main office with about 14 remote units (on DSL) connected via pptp in RouterOS and they are functioning just fine. We have one problematic office, however. It is connected via MPLS VPN link (non-mikrotik, not managed by me) to their ISP. There is a static route entered in the MPLS adtran box which forwards all traffic destined to the main office to a mikrotik which I have deployed on-site. So from workstation to corporate office the routing is as follows:
workstation > adtran (default gateway) > mikrotik > adtran > ISP > corporate office
The problem is that users’ RDP connections are timing out/freezing and print jobs are failing, which are symptoms of tcp fragmentation. I have lowered the mikrotik’s pptp-client default mtu/mru settings to 1430 which helped but did not solve the problem.
I think there is some MPLS related MTU issue that I’m not aware of, perhaps the l2mtu command needs tweaking?
Any help you could provide would be appreciated as I’m not very familiar with MPLS VPNs.
thanks,
Rob