Re: Peering best practices advice needed.

[Richard Irving <rirving () antient org>]

acennami () neupath com wrote:
> That is what he is doing, however if he is advertising the two /19's, 
>from two disconnected sites with the same ASN,
> they will not be able to reach each other as BGP will
>interpret this as a path loop.


  Yup.  I would presume, as they aren't connected, nor running
iBGP, they would be running different ASN's.

  Anything else hurts.


> On Wed, Dec 08, 2004 at 12:56:13PM -0500, Richard Irving wrote:
>
> > Rolo Tomassi wrote:
> >
> > > Hi all,
> > >
> > > Please forgive the simplistic nature of the query..
> > >
> > > Basically my company is multi-homed with 2 different providers in the 
> > > UK, and advertising a /18. Now some colleaguges in another part of the 
> > > world want to break that /18 into two /19's and advertise one /19 and we 
> > > advertise the other. This is fine, however we are NOT running IBGP in 
> > > the core, therefore the UK customers in the /19 will not be able to 
> > > reach the other /19 as there would be a loop detected through EBGP.
> >
> >   Pardon my simplistic solution, try dropping the /18, and -only-
> > advertise the corresponding /19 from each region.
> >
> >
> > > Now someone mentioned that we could use AS-LOOP-IN feature which will 
> > > overcome this problem and allow us to route to each other via EBGP. I 
> > > really think this is a bad idea but until we get an internal link - I 
> > > dont see a way forward. So... anyone doing this currently in their 
> > > network or have any "best practices" way round this. I want our company 
> > > to be good Netizens but still be able to pass traffic between the 2 /19's.
> >
> >  See above. K.I.S.S. (No offense intended ;)
> >
> >
> > > Any help would be greatly appreciated.
> > >
> > > Rolo !
> > >
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