Duplicate Packets...

[David Lang]

On Mon, 14 Jan 2002, Cyril Lalloum wrote:

> Date: Mon, 14 Jan 2002 17:49:45 +0100 (CET)
> From: Cyril Lalloum <clalloum@ipercast.net>
> To: Patrick Schaaf <bof@bof.de>
> Cc: netfilter@lists.samba.org
> Subject: Re: Duplicate Packets...
>
> On Mon, 14 Jan 2002, Patrick Schaaf wrote:
>
> >
> > Hi Cyril,
> >
> > >=A0I explain :)
> > >
> > >=A0I have a VIP and 5 real servers behind, for example ; I want =
each packet
> > >=A0which arrived on the VIP to be redirected on every real server.
> >
> > Weird setup. Really weird... What do you expect those packets to be
> > in terms of protocol (udp, tcp, whatever?) and/or port? Will the =
servers
> > somehow answer to the packets, or just capture them?
> >
>
> Yes, I imagine that is a weird thing...
> But in my case it should work whithout any conflict... i hope
>
> The real servers will just capture the streams and will act in
> consequence, no particular action to do on packets ; it's a one-way =
stream
> :)
>
> protocol should be tcp most of time but could be udp too.
>

if it's tcp which of the 5 servers sends the ack packet?

>
>
> > >=A0So i would like the 5 real servers to receive exactly the same =
packets.
> >
> > Hmm. Maybe using the subnet broadcast address would just work? That =
would
> > maybe require undoing whatever your boot scripts did to the stuff =
under
> > /proc/sys/net/ipv4/. It works for ping, it should work for UDP =
also.
> >
>
> I guess that the subnet braodcast address won't be enough because =
server
> have to be bind to the IP, and in an other hand with tcp i don't know =
what
> could be the session...
>
>
>
> > On your direct approach: no, I know of no iptables target which =
duplicates
> > or somehow multiplicates an incoming packet. And that's a good =
thing,
> > in general...
>
>
> thinks,
>
>
>
>
> --
> Cyril Lalloum
>
>