I have two Mikrotik devices with system version 6.49.2, one is RB 4011 (as VPN client) and one is x86 (as VPN server), I proxy from RB 4011 with L2TP (No IPsec) to x86, and access the Internet through the x86 WAN
I know i should use PMTUD to automatically match the best MSS value, but how do you make rules in Mangle to match the best value?
Normally, the logic should be like this
My traffic goes out from the L2TPOut of 4011, enters from the L2TP IN of x86, and finally goes out through the WAN port to finally access the Internet. How should I do for the mangle interface matching rules when setting mss? Or IP matching rules?
I seem to have a problem matching data in IP Mangle (on chain), what is the difference between Forward and Prerouting and Postrouting in Chain? How should I set them?
Some of my friends told me that the DF bit should be set to 1 when i setting the MSS, what does this setting do?
Forward and read the rest overhere: https://help.mikrotik.com/docs/display/ROS/Mangle#Mangle-Configurationexample