[116299] in North American Network Operators' Group
Re: Subnet Size for BGP peers.
daemon@ATHENA.MIT.EDU (Nathan Ward)
Wed Jul 29 17:52:05 2009
From: Nathan Ward <nanog@daork.net>
To: nanog list <nanog@nanog.org>
In-Reply-To: <15a18b860907291259n304fe598x763b650a6f0dc44a@mail.gmail.com>
Date: Thu, 30 Jul 2009 09:51:03 +1200
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 30/07/2009, at 7:59 AM, Jim Wininger wrote:
> I have a question about the subnet size for BGP peers. Typically
> when we
>
> turn up a new BGP customer we turn them up on a /29 or a /30. That
> seems to
>
> be the "norm".
>
>
> We connect to many of our BGP peers with ethernet. It would be a
> simple
>
> matter to allocate a /24 for connectivity to the customer on a
> shared link.
>
> This would help save on some address space.
>
>
> My question is, is this in general good or bad idea? Have others
> been down
>
> this path and found that it was a bad idea? I can see some of the
> pothols on
>
> this path (BGP session hijacking, incorrectly configured customer
> routers
>
> etc). These issues could be at least partially mitigated. Are there
> larger
>
> issues when doing something like this or is it a practical idea?
What is your access network? Do you have a switch port per customer?
If so, look in to private VLANs on Cisco, or whatever similar feature
exists for your vendor.
--
Nathan Ward
