Re: BGP multihoming with two address spaces

[Faisal Imtiaz <faisal () snappytelecom net>]

Another thing to keep in mind that some providers will use local pref. as well for traffic engineering,
Looking at the TW Telecom Community strings, it would appear that they do...

http://www.onesc.net/communities/as4323/

http://www.onesc.net/communities/as3356/

Try using the communities to influence your traffic engineering.

BTW, I took a quick look at Routeviews looking glass for you ...

Here is what I see....

8.37.93.0/24 is only being advertised via your TW Telecom connection .... (Possible Filters issues with Level3 ?)
207.114.212.0/24 is being advertised via both TW Telecom and Level3.. and in case of Routeviews, it is preferring the 
Level3 connection.

The above is for inbound traffic only...

For outbound, if you want to use both connections, then you will have to create an ACL to change the Local Pref so that 
you can use one or the other provider as the preferred route.

Regards.


Faisal Imtiaz
Snappy Internet & Telecom
7266 SW 48 Street
Miami, FL 33155
Tel: 305 663 5518 x 232

Help-desk: (305)663-5518 Option 2 or Email: Support () Snappytelecom net 

----- Original Message -----
> From: "Adam Greene" <maillist () webjogger net>
> To: nanog () nanog org
> Sent: Wednesday, January 29, 2014 9:20:32 AM
> Subject: RE: BGP multihoming with two address spaces
>
> Perhaps L3 is preferring the routes it hears from TW over the ones it hears
> from you. Perhaps there is a community string you can attach to your
> announcements to one or both providers which can help you further manipulate
> what they do with your routes ...
>
> -----Original Message-----
> From: Joseph Jenkins [mailto:joe () breathe-underwater com]
> Sent: Wednesday, January 29, 2014 7:45 AM
> Cc: nanog () nanog org
> Subject: Re: BGP multihoming with two address spaces
>
> I am announcing two separate /24s.  8.37.93.0 and 207.114.212.0.
>
>
> Joe
>
> On Jan 29, 2014, at 4:21 AM, Sasa Ristic <ristic.sasa () gmail com> wrote:
>
> > How are you announcing your address space now?
> >
> > On Wed, Jan 29, 2014 at 12:32 PM, Joseph Jenkins
> > <joe () breathe-underwater com> wrote:
> > > I am seeking some feedback/help with my BGP configuration.  I am peering
> with two providers level3 and tw.  Unfortunately all of my address spaces
> are preferring the route over tw rather than level3.  I have tried
> Prepending my AS and the carriers AS to the path on the tw side and I see
> those update being accepted by internet routers, but everyone is still
> preferring to install the tw routes rather than level3.  I was trying to
> advertise each provider's address space out their connections and then use
> the other for backup.  Now however everything is coming in through tw and no
> one seems to like level3.
> > > Thanks in advance for any guidance or assistance.
> > >
> > > Joe
> >
> >
> >
> > --
> > Ristic Sasa
> > --
> > mob: +381652221123
> > fax: +381618208488
> > --
> > Molim Vas da ne štampate ovaj e-mail ukoliko Vam zaista nije potreban
> > na papiru. Hvala!