pppoe mss problem after upgrade

RouterOS General
1

I have a PPPoE problem after upgrading from 2.8.28 to 2.9.31. I have a DSL customer who now can’t use http://www.mygotvmail.com (a ssl site) properly. The site hangs indicating a mtu/mss problem. The only way I have found to fix it is to not use the change mss in the mangle rule.

Somehow this rule prevents him from working. Is this a bug? I have him
working by creating a profile for him that has “Change TCP MSS” set to off, but I am worried about the other users if there is a problem with the change mss mangle in 2.9.31.

I tried all the changes I could think of, 1 master mangle rule, changing
mtu, clamp-to-pmtu, even changed the mtu of the router attached to the MT.

2

It worked fine at 2.8.28, and it does not work at 2.9.31?? Bug perhaps?

3

/ ip firewall mangle
add chain=forward protocol=tcp tcp-flags=syn action=change-mss new-mss=1440 comment=“MSS FIX” disabled=no

this will help