Re: [nsp] BGP loop detection

From: Nick Kraal (nick@arc.net.my)
Date: Wed Jun 19 2002 - 01:46:11 EDT


Thanks all for your valuable advice.

I tried the "neighbor EBGP-address allowas-in" command on the customer's
routers but this did not work. So we requested that they put in static
routes to the next-hop router. Quite unsexy I think. This is until and have
recommended that they place an internal circuit between the 2 networks, run
an IGP and should not be utilizing us for inter-PoP connectivity. But in the
mean time this will have do.

Don't really know where to begin with implementing MPLS in an ISP network.
Most of literature out there is for IP-VPN networks.

Regards,

-nick/

----- Original Message -----
From: "Zaheer Aziz" <zaziz@cisco.com>
To: "pankaj" <pankaj@worldgatein.net>
Cc: <cisco-nsp@puck.nether.net>
Sent: Wednesday, June 19, 2002 12:48 AM
Subject: Re: [nsp] BGP loop detection

> At 04:01 PM 6/18/2002 +0530, pankaj wrote:
> >More easier solution is as Nick and Philip said.
> >
> >Use static route for eachother's /19 pointing to your router. Or just
> >use default route pointing to ur router.
> >Thats enough for the situation u describe
>
> Nick wrote "/19 is actually for two separate businesses; one a tier-2 ISP
and
> the other VoIP provider"
>
> I cant imagine a tier-2 ISP running statics and defaults. They dont have a
> backbone
> but certainly they should be aware of ups and downs of Internet routes.
> Moreover if
> Nick Kraal's company decided to run MPLS, this customer would be a perfect
> candidate
> for Carrier Supporting Carriers CsC described at.
>
>
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120
limit/120st/120st14/csc.htm
>
>
> My 2c
> Zaheer
>
>
> >--pankaj
> >
> >----- Original Message -----
> >From: "Zaheer Aziz" <zaziz@cisco.com>
> >To: "Nick Kraal" <nick@arc.net.my>
> >Cc: <cisco-nsp@puck.nether.net>
> >Sent: Monday, June 17, 2002 10:44 PM
> >Subject: Re: [nsp] BGP loop detection
> >
> >
> > > At 10:17 PM 6/17/2002 +0800, Nick Kraal wrote:
> > >
> > > Another option,if you continue to run EBGP with them, is to have
> >them
> > > configure
> > >
> > > neighbor EBGP-address allowas-in
> > >
> > > at their EBGP boxes peering with you.
> > >
> > > This will accept paths with local as in the AS_PATH. It is mainly
> >used in
> > > MPLS-VPN scenarios but can certainly be applicable here.
> > >
> > > Zaheer
> > > >We have a customer that has transit services from us. They have
> >split their
> > > >network into two /19 and run BGP with us at two different
> >locations. Each
> > > >/19 is actually for two seperate businesses; one a tier-2 ISP and
> >the other
> > > >VoIP provider. Two physically sperate networks are also running the
> >same ASN
> > > >and are to peer with each other via our network. There is no
> >internal
> > > >interconnectivity between them or any IGP running.
> > > >
> > > >The problem lies in that to reach each other they need to 'transit'
> >via our
> > > >network and according to BGP, one cannot announce back the client
> >prefixes
> > > >learnt from the other network and vice versa as both of them are
> >running the
> > > >same ASN. This is to prevent routing loops.
> > > >
> > > >In this case is there a method to overwrite this so that the first
> >/19
> > > >network will be able to reach the second /19 network via ours?
> > > >
> > > >Thanks in advance.
> > > >
> > > >-nick/
> > >
> > >
>



This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:13:47 EDT