Re: ping-pong phenomenon with p2p links & /127 prefixes

[Jeroen Massar <jeroen@unfix.org>]

[two replies in once before I truly fill up every one's mailboxes ;) ]

On 2010-08-16 11:46, Randy Bush wrote:
>>> I have no plans to ask Cisco and Juniper about this. I want /127 to
>>> continue working, and couldn't care less about subnet anycast for my
>>> core routers.
>>
>> I think you miss my point: they might finally comply with the specs one
>> day (if you ask or not, others might) and you will have forgotten about
>> this little subtle problem and upgrade your routers and voila your
>> network is broken.
> 
> then you will join us supporting the /127 document and it won't be a
> problem, will it.

When it is changed that way, indeed it won't be a problem any more as
that is then the standard and people can't be bitten by it anymore.

The big 'problem' I have with it that it is yet-another-special case.
Special cases should be kept to a minimum where possible.


On 2010-08-16 11:48, Ole Troan wrote:
[..]
> it is intentional.
> there is a command to enable support for subnet-router anycast if use
> of that is desired.

For your platform (which is then a resolved case), but maybe not others.

> is there _any_ operational experience with the use of the subnet
> router anycast address?

I've never found a real use for it.

> asking the question another way. is it still a good idea, or was it
> ever?

Currently I don't see the use. The only use seems to be an extra
annoying slide when one is explaining all the 'good stuff about IPv6' ;)

One would almost wonder about fully deprecating the subnet anycast
address.....

Greets,
 Jeroen