From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [RFC] interface for outgoing packet
Date: Thu, 08 Sep 2011 08:09:05 +0200
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To: Viral Mehta <viral.vkm@gmail.com>
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Le mercredi 07 septembre 2011 =C3=A0 20:24 -0400, Viral Mehta a =C3=A9c=
rit :
> Hi All,
>=20
> How reasonably I can assume that,
>=20
> on whatever interface, I received the last packet
> for a particular Socket Connection, the same interface will be
> used to SEND the next packet for same socket connection?
>=20

No

> I am collecting the logs on one of my test machines.
> And it shows, I can assume all the time that "interface" which receiv=
ed packet
> for some socket connection, the same will be used to send packet for
> that connection
>=20
> But, I am not sure if I am missing some scenarios
> or setup (for e.g., bonding) where it can be wrong ?
>=20
> It would be more help if some one can shed some light.

By default, a socket is not bound to one interface, so you cant assume
this.

Check SO_BINDTODEVICE socket option if you need it.