Re: Masquarede stalls?

[Alistair Tonner <Alistair@nerdnet.ca>]

On August 10, 2004 04:22 pm, Mészáros Gergely wrote:
> Thank you  ! It wooorks !
>
> That clamp-mss magic worked for me, so I consider myself lucky. ^^
>
> >   iptables -I FORWARD -i $INTERNAL_IF -p tcp --syn -j TCPMSS
> > --clamp-mss-to-pmtu
>
> Great!
>
> If it would be in the mangle table, i would dare to say i understand what
> it does, but this case ... how can it send a larger packet in a smaller
> one? magic :)

	Actually we don't stuff a larger packet in a smaller one.  
	The system that has this rule can ensure that its neighbours
	use the correct packet  size  ~~ Although I am not aware of the 
	specifics, I believe that there (is/are) more than one mechanism
	for managing this.

	Alistair...

	

	Anyone:
	Does this TCPMSS in mangle table actually mangle packet contents during the 
	TCP handshake and forcibly set the MSS in the handshake packets??
	(sorry -- tired tonight and can't figure the relevant lines in the source -- 
	other half had annual celebratory day today and we've had a nice night out)


>
> I tried Anthony's mangle version also but something must be missing here to
> make it work: iptables -t mangle -A POSTROUTING -o EXTIF -j TCPMSS
> --clamp-mss-to-mtu iptables v1.2.9: Unknown arg `--clamp-mss-to-mtu'
> Mabbe modules? Or I misspelled it?
>
> However it works, so i'm happy.
> Thank you very much both of you, gurus ! :)
> If you come to Budapest, you are my guest for a beer !
>
> 1 MonK