MTU Packet size ; 2x MikroTik devices

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MobileAllOver

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I have two mikrotik devices, one acting as the main AP and the second functioning as a client on the first.

All other clients open a PPPoE connection to my main AP to obtain Internet Access via NAT. The second mikrotik device have 2 wireless interfaces - typical guesthouse setup. One connect as client, other must offer Internet Access without any further settings.

At this stage I have configured a second NAT rule (Masquerade / same / redirect option on Action tab). Internet connectivity seems to work, but certain web sites (including SSL) are extremely slowly.

Solutions I found that works
1. Create a PPTP connection to second AP - traffic via this connection
2. Using Windows Registry add a MTU entry for client's network card. 1488 works

I would like to enable all clients to have access to all sites without any further settings. I did try the "Packet Size" option in the Source Nat page, but this doesn't seem to work.

I would appreciate some help on this... The problem is that the end-user (client) working on the 2nd AP must be able to connect to the Internet via the 1st MikroTik device. This first device has one ADSL pppoe dialout and accepts only PPPoE / PPTP connections from clients
 
You can add a mangle rule to do this. Something like
/ip firewall mangle
add in-interface=? protocol=tcp tcp-options=syn-only action=passthrough tcp-mss=? comment="" disabled=no

Change interface and mss size to suite your setup.
Best to fiddle with mss, start at say 1452 and work your way down till you find the first value that works.
 
Question: Chain = prerouting / input / output / forward / postrouting?
I tried the Prerouting option - will only be able to test it tomorrow.

I do not get the tcp-options=syn-only option...
 
Action = change MSS? If this option is used, one cannot select prerouting / input.

And I did find the tcp-options - sorry, it getting late...
 
Ah, you have the newer versions of the Mikrotik that I have not yet tried. Its probably going to be prerouting, action=change mss. the tcp syn options must be there somewhere, as i recall they are a bit hidden in the new version.
 
My MikroTik forum address = MikroManagement. I posted the same issue there.

Just got a reply from their forum:
chain=forward protocol=tcp tcp-flags=syn action=change-mss new-mss=clamp-to-pmtu

It is (again) to late to test this, but I'll give it a try this weekend and post feedback.
 
Hey, I see u guys know how the MikroTik devices work. We are having hard time setting our router board up. It cant handle the bandwidth, too many users = slow internet, even if we disable p2p routing. Could you guys direct me to a link of a person that is able to offer advice and help with setup. Or could one of you guys maybe help.
Thanks in advance
 
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