disabling linux tcp receiver window auto tuning

linux, performance, tcp

Solution

Turn off auto-tuning of the TCP receive buffer size. On the receiver:

$ sudo sysctl net.ipv4.tcp_moderate_rcvbuf=0

Or

$ sudo echo 0 > /proc/sys/net/ipv4/tcp_moderate_rcvbuf

Problem

I'm working on `linux (2.6.43.8-1.fc15.i686.PAE)` and face some problem to disable auto tuning of the TCP receiver window. I'm trying to find a given setting that would force my client to advertise a fixed receiver window. I tried to give a same given value to `net.core.rmem_max` (/proc/sys/net/core/rmem_max) and `net.core.rmem_default` (/proc/sys/net/core/rmem_default) as well as `ipv4.tcp_rmem` (net.ipv4.tcp_rmem) but when checking the advertised window (using wireshark) it's absolutely not changing anything.... This is for a study of TCP behavior and I would be very greatful if someone could answer me Thanks in advance PS: I made use of this post to tune the parameters

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