From: Michael Wong (Michael.Wong@xxxxxxxxxx)
Date: Tue Aug 14 2001 - 03:50:47 GMT-3
Hans .... you're a good man !!!!
I've just come across this problem and couldn't work out why I wasn't getting t
he default routes to work. I thought the documentation or books were wrong. But
I tried a different IOS and what do you know ..... it worked.
Thanks for the info ...... MW
-----Original Message-----
From: Hans [mailto:yyao@sympatico.ca]
Sent: Friday, 10 August 2001 9:51 am
To: Murphy, Brennan; ccielab@groupstudy.com
Cc: Yves Fauser
Subject: Re: bgp default route--different question, same area
Hi Brennan and Yves,
Thanks for your response regarding my question.
I found out the problem: IOS version mismatch.
It has nothing to do with route map. It has nothing to do with the local
default network.
The rule is: a router can generate a bgp default using: neighbor xxxxx
default-originate without having a local 0.0.0.0 route, without using route
map.
My problem is the IOS version:
Here is my scenario:
R3--2.2.2.0--R1--1.1.1.0----R2
R1 established ebgp session with both R3 and R3. On R2 and R3, I have:
neigbbor 1.1.1.2 default-originate and neighbor 2.2.2.2 default-originate
configured.
Here is show ip bgp sum on R1:
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down
State/PfxRcd
1.1.1.2 4 4 18 19 2 0 0 00:15:52 0
2.2.2.2 4 6 16 15 2 0 0 00:12:52 1
Here is show ip bgp:
R1#sh ip bgp
BGP table version is 2, local router ID is 100.0.0.1
Status codes: s suppressed, d damped, h history, * valid, > best, i -
internal
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 0.0.0.0 2.2.2.2 0 6 i
That shows only R3 is advertising 0.0.0.0 to R1. R2 is not doing it.
Here is the show version info for R2:
R2#sh ver
Cisco Internetwork Operating System Software
IOS (tm) 2500 Software (C2500-DS-L), Version 12.0(5)T, RELEASE SOFTWARE
(fc1)
Copyright (c) 1986-1999 by cisco Systems, Inc.
Compiled Fri 23-Jul-99 04:12 by kpma
Here is the show version info for R3:
R3#sh ver
Cisco Internetwork Operating System Software
IOS (tm) 2500 Software (C2500-D-L), Version 12.0(8), RELEASE SOFTWARE (fc1)
Copyright (c) 1986-1999 by cisco Systems, Inc.
Compiled Mon 29-Nov-99 14:24 by kpma
Please note, on R2, the IOS is a desktop version which can do"show ip rip
database". while the version on R3 can not. I download this version on R2
with the information Yves gave to me. It seems this version on R2 did not
support bgp function very well.
Did anyone know what is the IOS version used in the CCIE lab?
Thanks,
Hans
----- Original Message -----
From: "Murphy, Brennan" <Brennan_Murphy@NAI.com>
To: "'Hans'" <yyao@sympatico.ca>; <ccielab@groupstudy.com>
Sent: Thursday, August 09, 2001 10:12 AM
Subject: RE: bgp default route--different question, same area
> The config I pasted below is supposed to work by testing for the
> presence of 200.100.50.0/24 and 100.50.25.0/24. If
> present, originate a default route to 152.16.3.65.
>
> If I shutdown the 200 and 100 networks, the default route
> is withdrawn from the 152 network as advertised. But
> if I then re-connect the 100 network, the default is
> not automatically originated. I have to plug in the
> 200 net to get the default to go out again.
> I noticed that the 200 net is first in the sequence
> of the ISP-RTR-UP prefix list. Does this play a role?
>
> The route map is supposed to detect whether either
> network is present and if so, send out a default.
> But it only seems to be concerned with the 200.
>
> Can anyone scan the config below and tell me why this
> is the case? ANother note: If i plug/unplug the 200
> net, the route is advertised/withdrawn like clockwork,
> automatically as expected. the 100 net does not work this
> way.
>
>
> bgp log-neighbor-changes
> network 152.16.3.0 mask 255.255.255.0
> neighbor 100.50.25.2 remote-as 65525
> neighbor 152.16.3.65 remote-as 65500
> neighbor 152.16.3.65 next-hop-self
> neighbor 152.16.3.65 default-originate route-map NEXT-HOP
> neighbor 152.16.3.65 distribute-list 20 out
> neighbor 200.100.50.2 remote-as 65000
> no auto-summary
> !
> ip classless
> no ip http server
> !
> !
> ip prefix-list ISP-RTR-UP seq 5 permit 200.100.50.0/24
> ip prefix-list ISP-RTR-UP seq 10 permit 100.50.25.0/24
> access-list 20 permit 152.16.3.0 0.0.0.255
> route-map NEXT-HOP permit 10
> match ip address prefix-list ISP-RTR-UP
>
>
>
>
>
> -----Original Message-----
> From: Hans [mailto:yyao@sympatico.ca]
> Sent: Thursday, August 09, 2001 12:41 AM
> To: ccielab@groupstudy.com
> Subject: bgp default route
>
>
> Hi all,
>
>
> Here is a paragraph I copied from Cisco website regarding the usage of
> neighbor default-originate command:
>
> "This command does not require the presence of 0.0.0.0 in the local
router.
> When used with a route map, the default route 0.0.0.0 is injected if the
> route map contains a match ip address clause and there is a route that
> matches the IP access list exactly. The route map can contain other match
> clauses also.
> You can use standard or extended access lists with the neighbor
> default-originate command."
>
> Examples
>
> In the following example, the local router injects route 0.0.0.0 to the
> neighbor 160.89.2.3 unconditionally:
>
> router bgp 109
> network 160.89.0.0
> neighbor 160.89.2.3 remote-as 200
> neighbor 160.89.2.3 default-originate
>
>
>
>
> However, when I tried it on my router, nothing happened at all.
>
>
> Any clues?
>
> Hans
> **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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