Bug#401435: debian-installer: sometimes net install does not work because of networking change in Linux 2.6.17 or later

[Santiago Vila <sanvila@unex.es>]

Package: debian-installer
Version: 20061102
Severity: important

This is really a feature more than a bug, but the adverse effects are
so devastating that it would be nice to have a workaround in
debian-installer, or have it properly documented in the install manual.

It seems there is a buggy router between me and the Internet. As a result,
apt-get does not work at all (it hangs, waiting for who knows what).
Needless to say, this is very bad if one wants to install Debian via
the Internet.

I found a thread in the linux kernel mailing list which explains
*exactly* my problem:

http://www.gatago.com/linux/kernel/9440712.html

Short summary: A change introduced in Linux 2.6.17 makes the network
not to work properly in some cases, due to buggy routers.

There is a trivial workaround:

echo 0 > /proc/sys/net/ipv4/tcp_window_scaling

However, I had to spend several afternoons to *diagnose* this problem
and realize what exactly the nature of the problem was.

Considering that the number of systems potentially affected is very big,
it would be nice if this were at least documented somewhere.

Thanks.