Cant get to microsoft.com, download.com, others!

Im having what seems to be a MSS/MTU problem but Ive tried everything I could think of, my setup is MT PPPoE, PPPoE server set to MTU 1480.. I have put the mangle rules for TCP MSS into mangle (found here), they are my only rules for mangle, as well as the basic firewall rules in filter.

I have 2 users connected to a AP/bridge , the only difference between the users is one is wireless, and the other is wired, the wired client works perfectly on all sites, but the wireless client cant surf the above sites, Ive tried MTU all the way down to 1404 with no luck, the mangle rules are getting processed, I have the change TCP-MSS turned to “no” in the pppoe profile. I dont know whats wrong!.. some testing shows that the client cant even traceroute past his radio, other times it does, but still wont load pages…

Im banging my head! Mangle rules:

0 ;;; [tcp], mss
chain=forward tcp-flags=syn action=jump jump-target=mss
1 ;;; [tcp], mss fixation
chain=mss protocol=tcp tcp-flags=syn tcp-mss=!536-1460 action=change-mss
new-mss=1440
2 ;;; [tcp], mss 1440 for mtu 1492
chain=mss protocol=tcp tcp-flags=syn tcp-mss=1453-65535
action=change-mss new-mss=1440
3 ;;; [tcp], mss ttl fix
chain=prerouting action=change-ttl new-ttl=set:65
4 ;;; [tcp], mss clamp-to-pmtu
chain=mss protocol=tcp tcp-flags=syn action=change-mss
new-mss=clamp-to-pmtu

Use the rule like this, if you want to change MTU,
[admin@MikroTik] > /ip firewall mangle add out-interface=pppoe-out protocol=tcp tcp-flags=syn action=change-mss new-mss=1300 chain=forward

OK I understand that rule, but I dont understand the “pppoe-out” interface, as I dont have one, all my users dynamically appear as a PPPoE interface as they connect. I cant select “pppoe-out” in winbox, I can only select specific users appears instead.

pppoe-out is the interface that connects to the Internet. Replace it with whatever you use.

Regards

Andrew