From: cebuano (cebu2ccie@cox.net)
Date: Thu Jan 16 2003 - 13:17:12 GMT-3
Dave,
I'm working on this Practical Design page...
http://www.cisco.com/univercd/cc/td/doc/cisintwk/ics/icsbgp4.htm#xtocid2
043946
And I just happened to notice this. I've never mocked up a lab to give
me this Gateway of Last Resort and a quad zero in the routing table so
this is a first for me.
Dimitris sent me the link that explains what I'm seeing...
http://www.cisco.com/en/US/tech/tk648/tk365/technologies_tech_note09186a
0080094374.shtml
Here's the config...
Thanks again.
Elmer
2511#s
!
interface Loopback10
ip address 203.250.13.41 255.255.255.0
!
interface Ethernet0
ip address 203.250.14.1 255.255.255.0
!
interface Serial0
ip address 128.213.63.1 255.255.255.252
!
router ospf 10
redistribute bgp 100 metric 2000 subnets
passive-interface Serial0
network 128.213.0.0 0.0.255.255 area 0
network 203.250.0.0 0.0.255.255 area 0
default-information originate metric 2000
!
router bgp 100
no synchronization
network 203.250.13.0
network 203.250.14.0
neighbor 128.213.63.2 remote-as 200
neighbor 128.213.63.2 route-map setlocalpref in
neighbor 203.250.15.2 remote-as 100
neighbor 203.250.15.2 update-source Loopback0
!
ip default-network 200.200.0.0
!
route-map setlocalpref permit 10
set local-preference 200
!
!
MC3810b#s
!
interface Ethernet0
ip address 192.208.10.6 255.255.255.252
!
interface Serial1
ip address 203.250.15.2 255.255.255.0
!
router ospf 10
redistribute bgp 100 metric 1000 subnets
passive-interface Ethernet0
network 192.208.0.0 0.0.255.255 area 0
network 203.250.0.0 0.0.255.255 area 0
default-information originate metric 1000
!
router bgp 100
network 203.250.15.0
neighbor 192.208.10.5 remote-as 300
neighbor 192.208.10.5 route-map LOCALONLY in
neighbor 203.250.13.41 remote-as 100
!
ip default-network 192.208.10.0
ip as-path access-list 1 permit ^300 500$
ip as-path access-list 2 permit ^300$
!
route-map LOCALONLY permit 10
match as-path 1
set local-preference 300
!
route-map LOCALONLY permit 20
match as-path 2
!
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
MADMAN
Sent: Thursday, January 16, 2003 6:58 AM
To: cebuano
Cc: ccielab@groupstudy.com
Subject: Re: Gateway of last resort V.S. 0.0.0.0
Do you have a "default-network" configuered on this router????
Dave
cebuano wrote:
> Hi all,
> Below are show output to demonstrate that Gateway of Last Resort
> supercedes path selection when forwarding to unknown networks. If
anyone
> has a URL to explain this behavior, please direct me to it. Thanks.
>
> 2511#ir
>
> Gateway of last resort is 128.213.63.2 to network 200.200.0.0
>
> 1.0.0.0/32 is subnetted, 1 subnets
> C 1.1.1.1 is directly connected, Loopback0
> 192.208.10.0/24 is variably subnetted, 2 subnets, 2 masks
> O E2 192.208.10.0/24 [110/1000] via 203.250.14.2, 00:02:59,
Ethernet0
> O 192.208.10.4/30 [110/84] via 203.250.14.2, 00:02:59, Ethernet0
> 203.250.15.0/24 is variably subnetted, 2 subnets, 2 masks
> B 203.250.15.0/24 [200/0] via 203.250.15.2, 00:02:58
> O 203.250.15.0/30 [110/74] via 203.250.14.2, 00:02:59, Ethernet0
> 128.213.0.0/16 is variably subnetted, 2 subnets, 2 masks
> B 128.213.0.0/16 [20/0] via 128.213.63.2, 00:02:34
> C 128.213.63.0/30 is directly connected, Serial0
> C 203.250.14.0/24 is directly connected, Ethernet0
> C 203.250.13.0/24 is directly connected, Loopback10
> O*E2 0.0.0.0/0 [110/1000] via 203.250.14.2, 00:01:08, Ethernet0
> B* 200.200.0.0/16 [20/0] via 128.213.63.2, 00:01:13
> O E2 195.211.0.0/16 [110/1000] via 203.250.14.2, 00:01:43, Ethernet0
>
>
> 2511#trace 100.100.100.1
>
> Type escape sequence to abort.
> Tracing the route to 100.100.100.1
>
> 1 128.213.63.2 [AS 200] 16 msec 16 msec 20 msec
> 2 128.213.63.2 [AS 200] !H * !H
>
>
> MC3810b#ir
>
> Gateway of last resort is 192.208.10.5 to network 192.208.10.0
>
> * 192.208.10.0/24 is variably subnetted, 2 subnets, 2 masks
> B* 192.208.10.0/24 [20/0] via 192.208.10.5, 00:04:49
> C 192.208.10.4/30 is directly connected, Ethernet0
> 203.250.15.0/30 is subnetted, 1 subnets
> C 203.250.15.0 is directly connected, Serial1
> 128.213.0.0/16 is variably subnetted, 2 subnets, 2 masks
> O E2 128.213.0.0/16 [110/2000] via 203.250.15.1, 00:04:23, Serial1
> O 128.213.63.0/30 [110/138] via 203.250.15.1, 00:04:51, Serial1
> O 203.250.14.0/24 [110/74] via 203.250.15.1, 00:04:52, Serial1
> 203.250.13.0/24 is variably subnetted, 2 subnets, 2 masks
> O 203.250.13.41/32 [110/75] via 203.250.15.1, 00:04:52, Serial1
> B 203.250.13.0/24 [200/0] via 203.250.13.41, 00:04:50
> O*E2 0.0.0.0/0 [110/2000] via 203.250.15.1, 00:02:57, Serial1
> O E2 200.200.0.0/16 [110/2000] via 203.250.15.1, 00:03:04, Serial1
> B 195.211.0.0/16 [20/0] via 192.208.10.5, 00:03:33
>
>
> MC3810b#trace 100.100.100.1
>
> Type escape sequence to abort.
> Tracing the route to 100.100.100.1
>
> 1 192.208.10.5 [AS 300] 0 msec 4 msec 4 msec
> 2 192.208.10.5 [AS 300] !H * !H
> .
-- David Madland CCIE# 2016 Sr. Network Engineer Qwest Communications 612-664-3367"You don't make the poor richer by making the rich poorer." --Winston Churchill . .
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