From: Nick Shah (nshah@xxxxxxxxxxxxxx)
Date: Thu Apr 11 2002 - 03:00:25 GMT-3
Gregg, is it possible to post configs here, including sh ip ro, since I
would be interested in knowing how R9 and R7 are deriving each other;s
addresses from (statics pointing R6s way bothways, or via OSPF)..
Sure its a curly one, but I think its possible.. Could we use policy routing
as well ? (is it an option). Since we need to go beyond the next hop
functionality, we may need to tweak the next hops differently.
Nick
----- Original Message -----
From: "Gregg Malcolm" <greggm@sbcglobal.net>
To: "Nick Shah" <nshah@connect.com.au>; <ccielab@groupstudy.com>
Sent: Thursday, April 11, 2002 3:52 PM
Subject: Re: BGP Configuration Question
> Nick,
>
> Absolutely..OSPF is running on all 3 tho I've changed the admin dist's to
be
> higher where needed (I hope). I sure hope I didn't miss anything really
> stupid because I know what an eyesore is it to look at config's like these
> :)
>
> ----- Original Message -----
> From: "Nick Shah" <nshah@connect.com.au>
> To: "Gregg Malcolm" <greggm@sbcglobal.net>; <ccielab@groupstudy.com>
> Sent: Wednesday, April 10, 2002 10:29 PM
> Subject: Re: BGP Configuration Question
>
>
> > Is running an IGP in between these 3 routers an option ??
> >
> > Nick
> > ----- Original Message -----
> > From: "Gregg Malcolm" <greggm@sbcglobal.net>
> > To: <ccielab@groupstudy.com>
> > Sent: Thursday, April 11, 2002 2:52 PM
> > Subject: BGP Configuration Question
> >
> >
> > > This is definitely not a real world question, only to help my
> > understanding.
> > > Here's the scenario :
> > >
> > > Physical diagram :
> > >
> > > R7---serial---R6---serial---R9
> > > | |
> > > 60 <---------- 90 <------ Loopback/Token-ring
> Addresses
> > >
> > >
> > > BGP Neighbor Connectivity and AS #'s
> > >
> > > R6---peers---R7---peers---R9
> > > 65256 79 79
> > >
> > > Test is to ping/trace between the 60 and 90 int's. Must use BGP
routing
> > for
> > > reachabilty between these 3 routers. There are many issues as I see
it
> > with
> > > this config.
> > >
> > > Here are the IP route tables from the 3 routers:
> > >
> > > R6
> > > C 150.20.60.0/24 is directly connected, Loopback60
> > >
> > > B 150.20.90.0/24 [20/0] via 150.20.50.7, 01:31:21 <----50.7 is R7
> > >
> > > R7
> > >
> > > B 150.20.60.0 255.255.255.0 [20/0] via 150.20.50.6, 01:32:52 <---50.6
is
> > R6
> > >
> > > B 150.20.90.0 255.255.255.0 [200/0] via 150.20.69.9, 01:33:10 <---69.9
> is
> > R9
> > >
> > > R9
> > >
> > > B 150.20.60.0/24 [200/0] via 150.20.50.7, 00:00:09
> > >
> > > C 150.20.90.0/24 is directly connected, TokenRing0
> > >
> > > I know the logical solution to this problem is to peer across the
> directly
> > > connected interface (I.E. R6 should peer with both R7 and R9), but I
> don't
> > > want to do that. One of the problems I'm seeing is when I try to ping
> > from R6
> > > to R9. R7 sends and ICMP redirect back to R6 saying that R6 know how
to
> > get
> > > to R9, even tho the route table clearly indicates that the .90 subnet
> has
> > the
> > > correct entries in both R6 and R7. R6 is in fact the path that the
> packet
> > must
> > > take since it has the interface connected to R9. Then of course, R6
> sends
> > the
> > > packet back to R7 again..classic routing loop. BTW - R7 cannot ping R9
> > either.
> > >
> > > Has anyone else experimented with a config like this (or already knows
> the
> > > solution) ? I ran across it accidentally when I was configuring local
> > pref
> > > and med.
> > >
> > > Thanks, Gregg
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:58:05 GMT-3