[Shorewall-users] Way OT: MSS/MTU question.

Joshua Banks l0f33t at yahoo.com
Tue Dec 16 14:24:30 PST 2003

--- chris <ck2 at softhome.net> wrote:

> In any case, is this leading to an answer to the original question?

To funny. Forgot about the original question. But to answer, I've found
so far that this must be a bug in the kernel routing table. I've packet
sniffed while doing ftp, smtp and http tranfers and the mss value in
the packet traces is never 40 for either machines participating the

But what I do see. is that I always advertise my mss value as being my
max mtu "-40" and most others do the same. So this would follow the RFC
1122. So I assume that this is just a stupid insignificant bug in the
kernel reporting this value incorrectly. Right now I'm using a dial-up
connection. We'll see if they're any significant changes in the mss
value recorded in the routing table when I switch from dial-up to
Comcast cable internet.

What do your values state Chris from doing a "netstat -rn" or a "route
-nee" ? Just out of curiousity.

Joshua Banks

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