Problems with IP fragments

[Andre Albsmeier]

On Tue, 10-Feb-2015 at 13:49:23 +0300, Lev Serebryakov wrote:
> On 10.02.2015 00:21, Andre Albsmeier wrote:
> 
> > The ipfw man page says:
> > 
> > Usually a simple rule like:
> > 
> > # reassemble incoming fragments ipfw add reass all from any to any
> > in
> > 
> > is all you need at the beginning of your ruleset.
> > 
> > However, I could never make this work. It eats all fragments but 
> > the resulting final packet never makes it. I am back to
> > 
> > ipfw -q add 1 pass udp from any to $myip frag in recv $ifc
> > 
> > as I need it only for UDP. Frag reassembly in pf works well on the
> > other hand...
> reass works for me, but kills all IPv6 packets, so it should be "reass
> ip4 from any to any in [recv $iface]"

Hmm, I tried again with ipv4 but this doesn't help (I don't use v6
anyway here). But it seems to work as soon as I switch off layer2
filtering. Normally I use net.link.ether.ipfw=1 (and, yes, I have
the appropriate arp rules installed). As soon as I switch this to
off, reassembly works. However, I have no idea why the reass code
messes around with layer2...

	-Andre

> 
> 
> -- 
> // Lev Serebryakov AKA Black Lion

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