On Wed, Jan 15, 2014 at 1:26 PM, William Herrin <bill@herrin.us> wrote:
On Wed, Jan 15, 2014 at 12:54 PM, Niels Bakker <niels=nanog@bakker.net> wrote:
* nanog@shankland.org (Jim Shankland) [Wed 15 Jan 2014, 18:04 CET]:
So ... RFC1918 addresses for the IXP fabric, then?
(Half kidding, but still ....)
They need to be globally unique.
Hi Niels,
Actually, they don't. To meet the basic definition of working, they just have to be able to originate ICMP destination unreachable packets with a reasonable expectation that the recipient will receive those packets. Global uniqueness is not required for that. However, RFC1918 addresses don't meet the requirement for a different reason: they're routinely dropped at AS borders, thus don't have an expectation of reaching the external destination.
Of course working, monitorable and testable are three different things. If my NMS can't reach the IXP's addresses, my view of the IXP is impaired. And "the Internet is broken" is not a trouble report that leads to a successful outcome with customer support... it helps to be able to pin things down with some specificity.
Regards, Bill Herrin
Using RFC1918 would incur the assumption that one will need to use a unique router or routing instance for every exchange connected to since exchanges are likely to have overlapping space at that point (RFC1918 IXP registry anyone?). I don't think it'd be a good idea to go down that path.. Also mentioned in a past nanog was the idea of potentially getting someone like team cymru to setup all exchange prefixes in a special bogon list and you could null route on your edge all those prefixes.. I inquired to team cymru about this back when originally discussed but never got anywhere with them.
-- William D. Herrin ................ herrin@dirtside.com bill@herrin.us 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004
-- [stillwaxin@gmail.com ~]$ cat .signature cat: .signature: No such file or directory [stillwaxin@gmail.com ~]$