[88189] in North American Network Operators' Group
Re: Split flows across Domains
daemon@ATHENA.MIT.EDU (Joe Abley)
Tue Jan 24 13:17:23 2006
In-Reply-To: <87fynd7b23.fsf@valhalla.seastrom.com>
Cc: "Christopher L. Morrow" <christopher.morrow@verizonbusiness.com>,
Glen Kent <glen.kent@gmail.com>, NANOG list <nanog@merit.edu>
From: Joe Abley <jabley@isc.org>
Date: Tue, 24 Jan 2006 13:14:57 -0500
To: Robert E.Seastrom <rs@seastrom.com>
Errors-To: owner-nanog@merit.edu
On 24-Jan-2006, at 13:09, Robert E.Seastrom wrote:
> Joe Abley <jabley@isc.org> writes:
>
>> If you can get two candidate routes for the same destination into the
>> FIB, then you'll get per-flow load balancing as long as CEF is
>> running, no?
>
> Yes and no. CEF is {src, dst} hash IIRC, and "per-flow" usually means
> {src, srcport, dst, dstport, [proto, tos]} hash in my experience.
Even if the hash is only calculated over source and destination IP
addresses, the end effect is still that packets associated with a
single flow still follow the same route where there is more than one
candidate route available.
Joe
