for linux i used to create mangle lines with Clamp TCp MSS option to avoid pppoe pmtu problems. Do i need setting something like that for
juniper mx?
Example of linux rules:
-A FORWARD -o ppp+ -p tcp -m tcp --tcp-flags SYN,RST SYN -m tcpmss --mss 1453:65535 -j TCPMSS --set-mss 1452
-A FORWARD -i ppp+ -p tcp -m tcp --tcp-flags SYN,RST SYN -m tcpmss --mss 1373:65535 -j TCPMSS --set-mss 1372