Regarding source based outbound routing (with redundancy)

Sat Oct 5 18:43:47 UTC 2013

On Sat, Oct 5, 2013 at 2:08 PM, joel jaeggli <joelja at bogus.com> wrote:
>
> On Oct 5, 2013, at 9:45 AM, Christopher Morrow <morrowc.lists at gmail.com> wrote:
>
>> you really don't want to do policy routing :(
>>
>
> PBR has this tendency to be brittle in the face of topology changes.

yup, exactly my point :(

> There are much better way to outbound load-balance between providers offering same or similar quality routes to the same destination.
>
> multi-AS multipath will do that if the peers are on the same router. BGPaddpath
> can do it for you if the peers are spread across routers.

these both will require seeing the longer prefix from the right peer
though, right? and selecting that would just be like natural selection
anyway...

yikes, I suppose you could:
  1) generate the longer prefix internally
  2) set it's next-hop to something reachable out both (all) peers
  3) metric the preferred peer's next-hop appropriately
  4) profit

but that sounds also kind of messy and prone to odd failures when
changes are made :(
you'd be adding complexity that you'd have to track through the life
of your network :( (and explain to anyone 'not you' working on the
network)

-chris

> joel
>
>> On Sat, Oct 5, 2013 at 12:19 PM, Anurag Bhatia <me at anuragbhatia.com> wrote:
>>> Hello there!
>>>
>>>
>>> I am trying to do a source based outbound routing between multiple
>>> upstreams. Usually I picked outbound via localpref but here I wish to use
>>> Provider 1 for say 10.10.10.0/24 while provider 2 for small chunk of it say
>>> 10.10.10.0/28. I wish to keep failover support and thus so if provider 2
>>> fails, I wish to push traffic again via Provider 1.
>>>
>>> Is this is possible only with VRF or I can push for some specific match
>>> rule in route maps?
>>>
>>>
>>>
>>> Thanks.
>>>
>>> --
>>>
>>>
>>>
>>> Anurag Bhatia
>>> anuragbhatia.com
>>>
>>> Linkedin <http://in.linkedin.com/in/anuragbhatia21> |
>>> Twitter<https://twitter.com/anurag_bhatia>
>>> Skype: anuragbhatia.com
>>
>