From: Peter van Oene (pvo@xxxxxxxxxxxx)
Date: Wed Jul 10 2002 - 09:26:36 GMT-3
It's a perfect answer in a production environment if you don't mind not
sending any routes to your customers who buy transit from you. They may
not agree with your solution entirely.
At 09:27 PM 7/10/2002 +1000, Nick Shah wrote:
>Dude,
>
>I had an escape path defined for myself ...
>"where mostly one router belongs to one AS, it may not be practically
>possible". That covers your NAP possibility.
>
>Yes, the assumption was made considering iBGP routers, which is quite common
>in ISP/NSP environment.
>That assumption also includes the fact that this border router has "only
>one, this one" external connection (because if it has another connection to
>another AS, we will still become a transit AS) as in NAP environment.
>
>So there are quite a few assumptions made. But, technically, this will still
>be a *perfect* answer.
>
>Note : I had also mentioned distribute lists(basically all forms of prefix
>filters) and community filtering, so I have the bases covered :). So we have
>to apply the solution considering all these facts (as and how applicable)
>
>rgds
>Nick
>----- Original Message -----
>From: Carlos G Mendioroz <tron@huapi.ba.ar>
>To: Nick Shah <nshah@connect.com.au>
>Cc: Tom Larus <tlarus@cox.net>; Jay Hennigan <jay@west.net>; John White
><jan_white7@hotmail.com>; <ccielab@groupstudy.com>
>Sent: Wednesday, July 10, 2002 9:14 PM
>Subject: Re: As Transit
>
>
> > How's that ?
> > That takes for granted that for being a transit AS you'll be traveling
> > through iBGP. That's not always the case.
> >
> > In a NAP, you may have one router with lots of neighbour ASs, and there
> > you might become transit even though you keep synch on.
> >
> >
> > Nick Shah wrote:
> > >
> > > This is a *perfect* answer in a production world.
> > >
> > > But in a controlled/lab environment, where mostly one router belongs to
>one
> > > AS, it may not be practically possible. That leaves only prefix
>filtering by
> > > no-community and/or all forms of prefix filters (distribute lists etc.)
> > >
> > > rgds
> > > Nick
> > >
> > > Message -----
> > > From: "Tom Larus" <tlarus@cox.net>
> > > To: "Jay Hennigan" <jay@west.net>; "John White" <jan_white7@hotmail.com>
> > > Cc: <ccielab@groupstudy.com>
> > > Sent: Wednesday, July 10, 2002 12:13 AM
> > > Subject: Re: As Transit
> > >
> > > > This is probably not what they are looking for, but if you leave synch
>on,
> > > > and do not redistribute bgp routes into you igp, you will definitely
>NOT
> > > > become a transit AS.
> > > >
> > > > Is the real answer to set all your incoming bgp routes to no-export?
> > > >
> > > > ---- Original Message -----
> > > > From: "Jay Hennigan" <jay@west.net>
> > > > To: "John White" <jan_white7@hotmail.com>
> > > > Cc: <ccielab@groupstudy.com>
> > > > Sent: Tuesday, July 09, 2002 12:39 AM
> > > > Subject: Re: As Transit
> > > >
> > > >
> > > > > On Tue, 9 Jul 2002, John White wrote:
> > > > >
> > > > > > Hi Guys,
> > > > > > I'm doing Cisco Aset lab.One of question is to prevent our AS from
> > > > becoming
> > > > > > Transit AS, but your not allowed to use AS path filtering.
> > > > > > Learning routes from outside shuould be still possible.
> > > > > > Somehow I can't think of anything else. Distribution
>list?Community
> > > > list?
> > > > >
> > > > > Hint:
> > > > >
> > > > > Look at the well-known community attributes.
> > > > >
> > > > > --
> > > > > Jay Hennigan - CCIE #7880 - Network Administration - jay@west.net
> > > > > NetLojix Communications, Inc. - http://www.netlojix.com/
> > > > > WestNet: Connecting you to the planet. 805 884-6323
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