Re: How to find a sick router with 2.6.17+ and tcp_window_scalingenabled

From: Alan Cox
Date: Tue Aug 15 2006 - 12:38:37 EST

Ar Maw, 2006-08-15 am 11:05 -0500, ysgrifennodd Mark Reidenbach:
> Does anyone have a way to find the broken router if you are not running
> the networks involved?

You are almost certainly looking for a broken/crap NAT box, firewall or
similar product. Routers that are just being routers don't touch the TCP
layer so even if they are broken/crap/ancient they won't do any harm to

The usual offenders are cheap NAT boxes and badly designed load
balancers. They may not even show up in a trace but you should expect
them to be at one end or the other, unless your ISP is providing you
with NATted addresses or some kind of managed security service.

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