TCP options order changed in FreeBSD 7,
incompatible with some routers
d.s. al coda
coda.trigger at gmail.com
Thu Mar 20 19:09:51 PDT 2008
On 3/12/08, Andre Oppermann <andre at freebsd.org> wrote:
> I'd be very interesting to know the exactly models and their firmware
> of the affected routers. If available locally I'd like to obtain a
> model myself for future regression tests.
Here are the models we managed to hear about via email:
Linksys WCG200 (with firewall enabled)
Encore Broadband Router
We didn't get any firmware version info that I know of. Hope this is still
> We've already fixed two issues. The first changes the order of the TCP
> and is in this change:
> It is to solve a problem observed by ISC that sounds very much like what
> describe. This fixed the issue in this case.
> The second changes the alignment padding from NOP to 0x00. Whether this
> a contributing factor to the reported problem is not clear. There hasn't
> been any specific test case for it. It was fixed because the RFC
> specifies 0x00
> to be used for padding and nothing else.
> It would be very helpful if you could apply these two patches after each
> to your 7.0 test server and find out together with the affected user(s)
> of these fixes the issue. If you can please try to test each one with and
> the routers firewall enabled. It is interesting to know whether the NAT
> firewalling part of the router chokes on it.
> We've been running with the patches for a few days now, and they seem to
fix the issue. We checked with one previously-affected user, and we haven't
received any reports of problems.
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