relocating packets

relocating packets

[Mark Oden]

Assuming I had two NICs in my machine that happen to be on the same 
network, is there a way to force packets of certain ports to use only 
one NIC or IP?

Thanks,

~Mark

Re: relocating packets

[/dev/rob0]

On Thursday 2005-October-13 04:50, Mark Oden wrote:
> Assuming I had two NICs in my machine that happen to be on the same
> network, is there a way to force packets of certain ports to use only
> one NIC or IP?

I believe this scenario is covered by the LARTC HOWTO.  In brief: use 
"-j MARK --set-mark 0xff" in mangle. Use dual routing tables, and a 
rule to put "fwmark 0xff" traffic in the alternate table. The mark can 
be anything from 0x0 to 0xffff.

http://lartc.org/howto/
-- 
    mail to this address is discarded unless "/dev/rob0"
    or "not-spam" is in Subject: header

Re: relocating packets

[Henrik Nordstrom]

On Thu, 13 Oct 2005, Mark Oden wrote:

> Assuming I had two NICs in my machine that happen to be on the same network, 
> is there a way to force packets of certain ports to use only one NIC or IP?

If you have multiple NICs in the same Ethernet broadcast segment then I 
would recommend you to enable "arp_ignore".

    echo 1 >/proc/sys/net/ipv4/conf/all/arp_ignore

If not things will get very confusing with traffic "randomly" coming in on 
either interface.

Once this is done you can firewall each NIC separately as you please, 
policy routing, marking etc to control how the interfaces are used.

Regards
Henrik