From: Alejandro Cadarso (a.cadarso@xxxxxxxxxxxxxx)
Date: Mon Sep 11 2000 - 14:38:01 GMT-3
Of course route maps are better, as Sam says, for example:
in R6 and R1
......
router bgp X
redistribute ospf 200 route-map internal
......
route-map internal permit 10
match route-type internal
Alejandro
Sam Munzani wrote:
>
> best way to deal mutual redistribution with ospf is route maps instead of
> distribution list. Distribution list brings type-5 or type-7 LSAs in
> protocol.
>
> Sam
> ----- Original Message -----
> From: "John Conzone" <jkconzone@home.com>
> To: "Aaron DuShey" <aaron.dushey@dushey-consulting.com>; "CCIE (E-mail)"
> <ccielab@groupstudy.com>
> Sent: Saturday, September 09, 2000 5:14 PM
> Subject: Re: routing loops
>
> > Aaron, I had a similar experience with lab 8, which I never did
> rectify.
> > I had my OSPF into BGP back into OSPF and yes, when I did I debug IP OSPF
> > packet, my problem was an external LSA being generated everytime my isdn
> > went down.
> > The link would go down, would send that into BGP on 1 router, who
> would
> > then send that back into OSPF, who would genreate the external LSA, and
> the
> > cycle continued.
> > If you debug ip ospf packet, you should see the route that is
> generating
> > the loop.
> > One good thing is I am going over route redistribution in both Doyles
> > and Caslows book.
> > Whenever I redistribute routes mutually, I filter out the native
> routes
> > from the other protocol's routes. So if I redistribute rip into ospf and
> > ospf back into rip, I filter out the rip routes inbound on the ospf
> process,
> > and the ospf routes in on the rip processes to prevent feedback. Of course
> > on the lab it won't be so easy!
> > Please let me know what you find out.
> >
> > ----- Original Message -----
> > From: "Aaron DuShey" <aaron.dushey@dushey-consulting.com>
> > To: "CCIE (E-mail)" <ccielab@groupstudy.com>
> > Sent: Saturday, September 09, 2000 5:39 PM
> > Subject: routing loops
> >
> >
> > > as3---r6---r5----r1-----as1
> > > 172.168.80.x as2 172.168.70.x
> > >
> > > OSPF is running only on r5
> > > r1 & r6 are doing mutal redistribution and running both ospf & bgp
> > > Looking at the results below my redistribution filtering isn't working
> as
> > > planned
> > >
> > > I want to make sure I understand what's happening here clearly-can
> someone
> > > verify please?
> > >
> > > r1 is redistibuting route 172.168.80.x in from BGP into OSPF, r6 ospf
> then
> > > adv to r5, r5ospf adv to r1 and BGP route is removed. BGP route is then
> > > re-entered, and loop is formed.
> > > Am I correct in saying this happens with type 5 (External) only since
> they
> > > are treated in a distance vector sort of manner in which they are
> > advertised
> > > by next-hops vs the normal LS behaviour of flooding?
> > > thanks,
> > >
> > > 01:43:00: RT: add 172.168.80.0/24 via 137.20.60.1, bgp metric [200/0]
> > > 01:43:05: RT: closer admin distance for 172.168.80.0, flushing 1 routes
> > > 01:43:05: RT: add 172.168.80.0/24 via 137.20.25.2, ospf metric [110/30]
> > > 01:43:10: OSPF: Rcv hello from 137.20.224.5 area 2 from Ethernet0/0
> > > 137.20.25.2
> > > 01:43:10: OSPF: End of hello processing
> > > 01:43:11: RT: del 172.168.80.0/24 via 137.20.25.2, ospf metric [110/30]
> > > 01:43:11: RT: delete subnet route to 172.168.80.0/24
> > > 01:43:13: RT: add 172.168.80.0/24 via 137.20.60.1, bgp metric [200/0]
> > > 01:43:16: RT: closer admin distance for 172.168.80.0, flushing 1 routes
> > > 01:43:16: RT: add 172.168.80.0/24 via 137.20.25.2, ospf metric [110/30]
> > > 01:43:20: OSPF: Rcv hello from 137.20.224.5 area 2 from Ethernet0/0
> > > 137.20.25.2
> > > 01:43:20: OSPF: End of hello processing
> > > 01:43:21: RT: del 172.168.80.0/24 via 137.20.25.2, ospf metric [110/30]
> > > 01:43:21: RT: delete subnet route to 172.168.80.0/24
> > > 01:43:23: RT: add 172.168.80.0/24 via 137.20.60.1, bgp metric [200/0]
> > > 01:43:26: RT: closer admin distance for 172.168.80.0, flushing 1 routes
> > > 01:43:26: RT: add 172.168.80.0/24 via 137.20.25.2, ospf metric [110/30]
> > > 01:43:30: OSPF: Rcv hello from 137.20.224.5 area 2 from Ethernet0/0
> > > 137.20.25.2
> > > 01:43:30: OSPF: End of hello processing
> > > Aaron DuShey
> > >
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