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kchris
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Posts: 62
Joined: Wed Oct 27, 2004 2:58 pm

ADSL sharing MTU problem

Thu Oct 27, 2005 4:57 pm

hi!

I've a strange situation:
I've created a simple config: sharing an ADSL connection with MT.
ADSL has MTU of 1480.
internal network ethernet card 1500.
clients: 1500.

some of the webpages don't load.
If I modify the CLIENT's MTU to 1450 all problems go away.
But: there are almost 30 clients - I don't want to go through EVERY PC and modify the MTU...

Is there a simple way to modify some of the MT's MTUs or config to solve this problem?

Before MT there was a very simple ADSL router and this problem was unknown...

thanks.
 
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HarvSki
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Posts: 395
Joined: Fri May 28, 2004 3:37 pm
Location: London, UK

Thu Oct 27, 2005 5:06 pm

you can use the firewall mangle rules to fix this:

4 X ;;; change tcp mss for pppoe connections
src-address=192.168.43.0/24 protocol=tcp tcp-options=syn-only
action=passthrough tcp-mss=1360

as you can see I mangle it to 1360 - it seems to make the trafic floe nicely
 
kchris
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Topic Author
Posts: 62
Joined: Wed Oct 27, 2004 2:58 pm

Thu Oct 27, 2005 7:20 pm

you can use the firewall mangle rules to fix this:

4 X ;;; change tcp mss for pppoe connections
src-address=192.168.43.0/24 protocol=tcp tcp-options=syn-only
action=passthrough tcp-mss=1360

as you can see I mangle it to 1360 - it seems to make the trafic floe nicely
thank you, saved my life 8) . to be exact I created a mangle whose action is "change MSS" instead of passthrough. I use version 2.9.6.