Need help to resolve this issue. 2 days ago we decided to upgraded one of 3
mono firewall to current version from
1.22  to 1.3b14. The upgrade path was from 1.22 to 1.3b7 to 1.3b14, overall
process was pretty smooth with no issues or errors etc.

However, since the upgrade internet browsing (external) from all machine is
office is painfully slow for most of the site and often times out. These are
well known sites ..i.e. microsoft.com,
 CNN.com etc.

WAN connection is DSL (PPPoE)

Hardware is Dell PC with Intel NICs, 512 MB RAM and 64 MB CF card.

I've also down grade to 1.3b2 with a brand new config without any custom
rules/nat etc and still no go, exact same issue websites timing out.
Furthermore, for sake of testing I changed the MTU setting on one of W2K3
servers to 1300 and immediately after rebooting websites started loading
normally on this server and I was able confirm that chaning did work on the
other XP machines.

In 1.22 there was a option to set the MTU which was set to 1400.

There is definitely a issue with MTU setting on firewall and I'm hoping I
can avoid changing the MTU setting on every machine in the office.

Any tips to resolve this?

Thanks
Greg