Re: CAN-2004-1137

On Monday, January  3 at 11:30 AM, quoth hilton de meillon:
>  I have been doing a bit of research - there are numerous instances of
> iptables scripts containing rules to block IGMP using iptables - am I
> correct in saying that IGMP is on the network layer IP protocol 2 hence all
> the iptables rulesets claiming to block igmp are misinformed ?.
> 
> Is there a igmptables or any other way of selectively blocking IGMP using
> linux ?.

IPtables blocks or accepts on a packet-by-packet basis (though it has 
extensions for connection-related packets). As such, of course it can 
block IGMP. It hooks into the network stack before packets are handed to 
the IP stack. IPtables can block all manner of packets, even 
strictly-speaking non-IP packets (e.g. ARP/RARP). The only thing it 
can't block is it can't prevent your ethernet card from receiving 
arbitrary ethernet frames, but it can prevent those frames from being 
processed at any higher level.

~Kyle
-- 
Anyway, have fun.
And don't bother reporting any bugs for the next few days. I won't care
anyway.
-- Linus Torvalds, when kernel 2.4 came out

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