[148262] in North American Network Operators' Group
Re: subnet prefix length > 64 breaks IPv6?
daemon@ATHENA.MIT.EDU (sthaug@nethelp.no)
Sat Jan 7 08:25:29 2012
Date: Sat, 07 Jan 2012 14:24:28 +0100 (CET)
To: bjorn@mork.no
From: sthaug@nethelp.no
In-Reply-To: <87lipjg1sk.fsf@nemi.mork.no>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
> "Note: An IPv4 route requires only one TCAM entry. Because of the
> hardware compression scheme used for IPv6, an IPv6 route can take
> more than one TCAM entry, reducing the number of entries forwarded
> in hardware. For example, for IPv6 directly connected IP addresses,
> the desktop template might allow less than two thousand entries."
>
>
> Translated: "The stated numbers for IPv6 routes are twice the real max.
> However, prefix compression may give better utilisation under certain
> conditions".
Thanks, that's the first *specific* information I've seen of equipment
that might have problems (reduced number of entries) with longer than
64 bit prefixes. Fortunately we're not using 3560/3750 for IPv6 routing
at the moment.
Any other takers?
Steinar Haug, Nethelp consulting, sthaug@nethelp.no
