From: caolw (caolw@xxxxxxxxxxxx)
Date: Mon Apr 30 2001 - 11:25:10 GMT-3
RE: about transit ASIf it is a lab question,what's your answer?
----- Original Message -----
From: Gabriel.Neagoe@snt.ro
To: caolw@fosco.com.cn ; ccielab@groupstudy.com
Sent: Monday, April 30, 2001 10:15 PM
Subject: RE: about transit AS
Hello
no matter what, the routes exiting from AS254 will have 254 added on the last
position in the as-path
this is not alterable by user configuration
so BGP loop avoidance will work
just try it and check with sh ip bgp in AS1 and AS254
-----------------------------------------------
Gabriel Neagoe, GN379-RIPE
Networking solutions consultant
Cisco Certified Network Professional
Cisco Certified Design Associate
S&T Romania
tel: +401 20 40 300
fax: +401 20 40 310
-----------------------------------------------
-----Original Message-----
From: caolw [SMTP:caolw@fosco.com.cn]
Sent: Monday, April 30, 2001 4:57 PM
To: Gabriel.Neagoe@snt.ro; Groupstudy
Subject: Re: about transit AS
I do not agree with you.
if within AS254 ,some links down,and some routes'
as-path changed,will AS1 be a transit AS?
----- Original Message -----
From: <Gabriel.Neagoe@snt.ro>
To: <caolw@fosco.com.cn>; <ccielab@groupstudy.com>
Sent: Monday, April 30, 2001 5:33 PM
Subject: RE: about transit AS
> the catch here is that as1 is double connected to AS254
>
> AS1 will never be a transit area for 254 beacuse of BGP's routing loop
> avoidance algorythm, so you have nothing to do about it
> BGP will do it itself
> :-)
>
>
> -----------------------------------------------
> Gabriel Neagoe, GN379-RIPE
> Networking solutions consultant
> Cisco Certified Network Professional
> Cisco Certified Design Associate
> S&T Romania
> tel: +401 20 40 300
> fax: +401 20 40 310
> -----------------------------------------------
>
> > -----Original Message-----
> > From: caolw [SMTP:caolw@fosco.com.cn]
> > Sent: Monday, April 30, 2001 10:26 AM
> > To: Groupstudy
> > Subject: about transit AS
> >
> > Hi,All:
> >
> > I have a question about BGP.
> >
> > (AS254)---r1-(AS1)-r2-(AS1)-r3--(AS254)
> >
> > 1. r1,r2,r3 are in AS1,
> > 2. r1,r3 are border router.r2 is RR.
> > peer is AS254
> > 3. the request is:donot let AS1 become a transit AS
> > 4. Donot use as-path filter.
> >
> > My answer is use Commumity attri.
> > I let r1 and r3's incoming routes set no-export.
> > and send-community to r2.
> > r2 send-community to r1 r3.
> >
> > But I know my answer is wrong.
> >
> > Is anyone have any other solutions?
> > Thanks.
> > **Please read:http://www.groupstudy.com/list/posting.html
> **Please read:http://www.groupstudy.com/list/posting.html
**Please read:http://www.groupstudy.com/list/posting.html
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