[183376] in North American Network Operators' Group
Re: BGP advertise-best-external on RR
daemon@ATHENA.MIT.EDU (Mohamed Kamal)
Tue Sep 1 08:55:57 2015
X-Original-To: nanog@nanog.org
To: Jeff Tantsura <jeff.tantsura@ericsson.com>,
Diptanshu Singh <diptanshu.singh@gmail.com>
From: Mohamed Kamal <mkamal@noor.net>
Date: Tue, 1 Sep 2015 14:51:27 +0200
In-Reply-To: <D20210A6.A4C08%jeff.tantsura@ericsson.com>
Cc: NANOG <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
Hi,
Diverse-path will only send the second best path, and in my case I have=20
three routes not two. In addition to that, every PE will have to peer=20
with the RR via a second session (on the same RR, as I will not deploy a=20
new standalone shadow RR) and this will increase the BGP sessions to the=20
double.
Add-path will have a network-wide IOS upgrade for this BGP capability to=20
be supported which is not viable now.
So, is there any other recommendation other than the internet VRF with=20
different RDs solution?
Regards,
Mohamed Kamal
Core Network Sr. Engineer
On 8/25/2015 11:37 AM, Jeff Tantsura wrote:
> Hi,
>
> In your case I=B9d recommend to use diverse path, due to its simplicity=
and
> non disruptive deployment characteristics.
> As you know - diverse path requires additional BGP session per addition=
al
> (second, next, etc) path, in most cases not a problem, however mileage
> might vary.
>
> To my memory, in Cisco land - it has only been implemented in IOS, not =
XR,
> please check.
>
> Cheers,
> Jeff
>
>
>
>
> -----Original Message-----
> From: Diptanshu Singh <diptanshu.singh@gmail.com>
> Date: Monday, August 24, 2015 at 10:53 PM
> To: Mohamed Kamal <mkamal@noor.net>
> Cc: "nanog@nanog.org" <nanog@nanog.org>
> Subject: Re: BGP advertise-best-external on RR
>
>> Yes . In the case of diverse path , shadow route reflector will be the
>> one wherever you enable commands to trigger diverse path computation.
>>
>> Good thing with diverse path is that the RR-Clients don't have to have
>> any support but bad thing is that it can only reflect One additional
>> best-path( second best path ) .
>>
>> Sent from my iPhone
>>
>>> On Aug 24, 2015, at 2:31 PM, Mohamed Kamal <mkamal@noor.net> wrote:
>>>
>>> It's only supported on the 15.2(4)S and later not the SRE train. I
>>> might consider an upgrade.
>>>
>>> One more question regarding this, can you configure the RR to be the
>>> main and shadow RR?
>>>
>>> Mohamed Kamal
>>> Core Network Sr. Engineer
>>>
>>>> On 8/24/2015 9:16 PM, Diptanshu Singh wrote:
>>>> BGP Add-Path might be your friend . You can look at diverse-path as
>>>> well .
>
