[179844] in North American Network Operators' Group
Re: Thousands of hosts on a gigabit LAN, maybe not
daemon@ATHENA.MIT.EDU (Benson Schliesser)
Fri May 8 16:26:08 2015
X-Original-To: nanog@nanog.org
Date: Fri, 08 May 2015 13:25:32 -0700
From: Benson Schliesser <bensons@queuefull.net>
To: nanog list <nanog@nanog.org>
In-Reply-To: <CAL9jLaYFw3ebLMxSx7hynxv15sVX1n+bZoU_dLhmVHpGMy3+SA@mail.gmail.com>
Cc: John Levine <johnl@iecc.com>
Errors-To: nanog-bounces@nanog.org
Morrow's comment about the ARMD WG notwithstanding, there might be some
useful context in https://tools.ietf.org/html/draft-karir-armd-statistics-01
Cheers,
-Benson
> Christopher Morrow <mailto:morrowc.lists@gmail.com>
> May 8, 2015 at 12:19 PM
>
> consider the pain of also ipv6's link-local gamery.
> look at the nvo3 WG and it's predecessor (which shouldn't have really
> existed anyway, but whatever, and apparently my mind helped me forget
> about the pain involved with this wg)
>
> I think 'why one lan' ? why not just small (/26 or /24 max?) subnet
> sizes... or do it all in v6 on /64's with 1/rack or 1/~200 hosts.
> John Levine <mailto:johnl@iecc.com>
> May 8, 2015 at 11:53 AM
> Some people I know (yes really) are building a system that will have
> several thousand little computers in some racks. Each of the
> computers runs Linux and has a gigabit ethernet interface. It occurs
> to me that it is unlikely that I can buy an ethernet switch with
> thousands of ports, and even if I could, would I want a Linux system
> to have 10,000 entries or more in its ARP table.
>
> Most of the traffic will be from one node to another, with
> considerably less to the outside. Physical distance shouldn't be a
> problem since everything's in the same room, maybe the same rack.
>
> What's the rule of thumb for number of hosts per switch, cascaded
> switches vs. routers, and whatever else one needs to design a dense
> network like this? TIA
>
> R's,
> John
