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Change the TCP Window size

Posted: Fri Feb 25, 2011 12:18 am
by adiazm
Hello everybody.

We are using RouterOS 3.30 under i386 (also we tried with RouterOS 4.16 and 5.0rc5)

We have this error trying to browse this website:

http://www.pacificar.com.ec

Connection Interrupted

The document contains no data.

The network link was interrupted while negotiating a connection. Please try again.



I replace my routerOS gateway with a Linux IPtables gateway and get the same error. But checking some options I found with this command that I run in my linux box.

[root@mail ~]# echo 4096 87380 262144 > /proc/sys/net/ipv4/tcp_rmem

Then the trouble was solved and we can browse that website.

How can we modify these kernel parameters in RouterOS?

We will appreciate your help.

Best Regards.

Antonio Díaz M.

Re: Change the TCP Window size

Posted: Fri Feb 25, 2011 1:01 pm
by normis
it doesn't work for me as well, so that's a problem with the website. i doubt that all their visitors install Linux and modify their Kernel just to browse one page :)

Email their admin, that's the best approach here.

Re: Change the TCP Window size

Posted: Fri Feb 25, 2011 3:16 pm
by adiazm
Hi Normis, thank you for the answer.

The main idea is replace Linux gateways with RouterBoard / RouterOS, but this is an issue that I have to get over.

I don't know why but some websites here in Ecuador, mostly government related, have this problem.

Anyway, if you use another gateway (cisco, huawei, checkpoint or another not-linux-based solution) don't have this issue.

Best regards.

Re: Change the TCP Window size

Posted: Fri Feb 25, 2011 3:20 pm
by normis
I will try to investigate

Re: Change the TCP Window size

Posted: Fri Feb 25, 2011 3:42 pm
by adiazm
Thanks Normis!

You Rule!!!!!

Re: Change the TCP Window size

Posted: Mon Feb 28, 2011 11:14 am
by normis
The tcp-window-size that you are setting with the mentioned command is directly linked to the amount of RAM. So, you could simply put more RAM into the machine to solve this issue (more RAM will increase TCP window size). This affects only the Webproxy in RouterOS, and from the description of the issue, looks like tcp-windows size is not the only problem, could be some configuration issue or undiscovered RouterOS proxy problem. Hard to say. But - disabling webproxy will also solve the issue.

Re: Change the TCP Window size

Posted: Mon Feb 28, 2011 5:47 pm
by Chupaka
*** ns1.xxxxxxxxx can't find www.pacificar.com.ec: Non-existent domain

Re: Change the TCP Window size

Posted: Mon Feb 28, 2011 6:14 pm
by adiazm
I´m sorry.

http://www.pacificard.com.ec

Best regards.

Re: Change the TCP Window size

Posted: Mon Feb 28, 2011 6:22 pm
by Chupaka
so, does it work with proxy disabled?

it works for me, I don't use proxy

Re: Change the TCP Window size

Posted: Tue Mar 01, 2011 8:34 am
by normis
that website is completely broken

Image

Re: Change the TCP Window size

Posted: Tue Mar 01, 2011 6:33 pm
by Chupaka
Normis, your "ERR_EMPTY_RESPONSE" and adiazm's "The document contains no data" sounds very similar ;)

seems like you both have the same problem, as the website works fine for me. and I still don't use webproxy

Re: Change the TCP Window size

Posted: Wed Mar 02, 2011 7:41 am
by normis
I have never seen this error in my life. That server is the problem for sure.

Re: Change the TCP Window size

Posted: Wed Mar 02, 2011 4:06 pm
by Chupaka
sorry to say that, but it's definitely proxy problem: when I enable proxy on one of my routers (it's x86 v4.2), I can browse any website except http://www.pacificard.com.ec/ %)

maybe GZIP encoding of webpage is the reason? can WebProxy work with compressed data?..

p.s. actually, after a minute or two, webpage opened... after refresh, it shown
<!DOCTYPE html PUBLIC "-
and stopped. one more page reload - four minutes, no reaction... when I disable proxy - I can browase the website smoothly

Re: Change the TCP Window size

Posted: Thu Mar 03, 2011 7:32 am
by normis
I understand that this is caused by the proxy, but why only one website? I have not seen this behavior with any other website, and I use proxy for a very long time.

Re: Change the TCP Window size

Posted: Thu Mar 03, 2011 3:51 pm
by Chupaka
your developers should trace that =)

for example, look at ticket 2010101966000509 (it's not my one, but I was commenting it to Sergejs) - was it solved? that webserver has one insignificant difference in its header part - and WebProxy cannot process it correctly