Yep you are right.
Lets try that again ...
a) connect up1 to the same ethernet segment
b) form bgp neighbor relationship with BGP peer at provider pr2
c) advertise appropriate MED values requesting that pr2 prefer
up2
d) set local preference to prefer link via up2 to pr2 over
up1 to pr2
In terms of what I am asking is, are there any issues with having two
'redundant' bgp links from two different routers in one AS over a single
multi-access link to a single router in another AS.
It seems to me that this would be a simple no-brainer type of change to
make, but I just have a nagging suspicion that there is some gotcha waiting
to jump out when you least expect it. None of the sample configurations I
have seen seem to mention this sort of config and I was wondering if there
was some reason why it shouldnt be done, or if it was just one of those
obscure variations of common configurations that did not warrant it's own
explicit mention.
Peter
--On 12 February 2003 14:27 +0000 Peter van Oene wrote:
> At 01:36 PM 2/12/2003 +0000, Peter Walker wrote:
>> Folks
>>
>> A quick question on external BGP connection configuration.
>>
>> Given an organisation (ORG) with 2 EBGP routers (up1, up2) and two
>> upstream providers (pr1, and pr2) where provider pr1 is currently linked
>> to the router up1 via a serial link and provider pr2 is currently linked
>> to router up2 via a traffic shaped and limited ethernet link. ORG is
>> does not allow transit between the providers.
>>
>> Is there any reason why ORG should not
>>
>> a) connect pr1 to the same ethernet segment
>> b) form bgp neighbor relationship with BGP peer at provider pr2
>> c) advertise appropriate MED values requesting that pr2 prefer
>> up2 d) set local preference to prefer link via up2 to pr2 over
>> up1 to
> pr2
>
>
> I'm not sure if you are messing up your prs and ups here, but I'm not
> following you entirely. Why would you not just peer both routers and use
> prepend/med and pref to control load like most folks do? Maybe explaining
> what is better or different about this approach would help explain what
> the approach is :)
>
> Pete
>
>
>
>
>
>> What I am looking for is technical (or business/political) reasons why
>> this is a good or bad idea.
>>
>> I understand that all this would give is redundancy at the router level
>> (up1, up2), the ethernet link and pr2's router are all still potential
>> single points of failure. I also understand that pr2 may not wish to
>> allow such a configuration.
>>
>> Also, what would need to be done to ensure that any changes made would
>> not have any impact on decisions regarding the routing choice between
>> pr1 and pr2?
>>
>> Regards
>>
>> Peter
> Nondisclosure violations to [EMAIL PROTECTED]
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=62875&t=62860
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
