What is the correct MTU for MS VPN server running on Windows 2000 server? I have configured MS VPN for Windows 2000 server with a single NIC and it didn’t work too well at first (connection was dropping after 5-10 minutes, Outlook wouldn’t work and terminal server doesn’t work) but then I changed the MTU setting on the VPN server itself to 1300 and things got a lot more stable. Connection doesn’t drop anymore, I can access all network resources and Outlook appears to be working now but Terminal Server refuse to work. When I try to connect to terminal server, a login window would come up but then I can’t see anything. It remains black for about a minute then it gives me an error saying cannot connect due to network error.
I tried setting the MTU 1400, 1200, 1100 and 1000 but 1300 seems to be the best so far because Outlook doesn’t time out. Can someone offer me some suggestions as to what I can do or change to improve the performance of my VPN? Would software compression on the RRAS have anything to do with this?
This is not a firewall issue since I have opened all VPN ports (1723, 47 and 3389).