RE: BGP Defaults -found problem-policy routing-question 2!

From: Aaron DuShey (aaron.dushey@xxxxxxxxxxxxxxxxxxxxx)
Date: Sat Sep 09 2000 - 16:45:22 GMT-3


   
I misunderstood the lab details. I thought we could configure no statics, so
I configured policy routing. Apparently, since BGP couldn't see the next hop
in the routing table it wouldn't install the default route. I since removed
policy routing and it works.
This brings up another question, what are the rules when using policy
routing with BGP. Does anyone have experience or comments here. This is a
very interesting issue. BGP will establish will EBGP multihop, but since it
cannot see a route to the multihop neighbor in the IGP routing table, no
updates will be advertised in the IRT(IP routing table).
hmmmmmm
?

Aaron DuShey

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Aaron DuShey
Sent: Friday, September 08, 2000 9:32 PM
To: CCIE (E-mail)
Subject: bootcamp lab8-BGP Defaults on r7-r1

Couple questions here
1st of all, whats the difference between these 3 BGP related commands
network 0.0.0.0
neighbor x.x.x.x default originate
default-information originate
2nd-Why isn't the BGP default 0.0.0.0 making it into the routing table?

Here are r2 + R7's configurations
thanks!

BGP table version is 4, local router ID is 200.200.100.1
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
*> 172.168.0.0 137.20.10.70 170 0 3 i
r1#i
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
       i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate
default
       U - per-user static route, o - ODR

Gateway of last resort is 137.20.25.2 to network 0.0.0.0

     200.200.200.0/32 is subnetted, 1 subnets
O IA 200.200.200.1 [110/75] via 137.20.25.2, 00:48:26, Ethernet0/0
     137.20.0.0/16 is variably subnetted, 11 subnets, 5 masks
O E1 137.20.200.16/28 [110/110] via 137.20.25.2, 00:48:26, Ethernet0/0
O IA 137.20.224.0/20 [110/1572] via 137.20.25.2, 00:48:26, Ethernet0/0
O IA 137.20.30.0/24 [110/80] via 137.20.25.2, 00:48:26, Ethernet0/0
C 137.20.25.0/24 is directly connected, Ethernet0/0
O IA 137.20.20.0/24 [110/84] via 137.20.25.2, 00:48:26, Ethernet0/0
C 137.20.10.0/24 is directly connected, FastEthernet1/0
O IA 137.20.60.1/32 [110/21] via 137.20.25.2, 00:48:26, Ethernet0/0
O E1 137.20.40.16/28 [110/110] via 137.20.25.2, 00:48:26, Ethernet0/0
O IA 137.20.33.0/24 [110/75] via 137.20.25.2, 00:48:26, Ethernet0/0
O IA 137.20.100.32/27 [110/74] via 137.20.25.2, 00:48:26, Ethernet0/0
O IA 137.20.64.0/20 [110/20] via 137.20.25.2, 00:48:26, Ethernet0/0
C 200.200.100.0/24 is directly connected, Loopback0
B 172.168.0.0/16 [20/170] via 137.20.10.70, 00:14:26
O*E2 0.0.0.0/0 [110/20] via 137.20.25.2, 00:48:27, Ethernet0/0
r1#r
Building configuration...

hostname r1
!
logging buffered 4096 debugging
!

interface Loopback0
 ip address 200.200.100.1 255.255.255.0
 no ip directed-broadcast
 ip ospf interface-retry 0
!
interface Ethernet0/0
 ip address 137.20.25.1 255.255.255.0
 no ip directed-broadcast
 ip ospf interface-retry 0
!

interface FastEthernet1/0
 ip address 137.20.10.1 255.255.255.0
 no ip directed-broadcast
 speed 10
!
router ospf 1
 network 137.20.25.1 0.0.0.0 area 2
 network 200.200.100.1 0.0.0.0 area 2
!
router bgp 2
 no synchronization
 neighbor 137.20.10.70 remote-as 3
 neighbor 137.20.10.70 update-source Loopback0
 neighbor 137.20.10.70 default-originate
 neighbor 137.20.64.6 remote-as 2
 neighbor 137.20.64.6 route-reflector-client
 neighbor 137.20.100.33 remote-as 2
 neighbor 137.20.100.33 route-reflector-client
 no auto-summary
!
ip classless

end

r1#

r7#
BGP table version is 2, local router ID is 172.168.70.1
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
* 0.0.0.0 200.200.100.1 0 2 i
*> 172.168.0.0 0.0.0.0 0 32768 i
r7#i
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
       i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate
default
       U - per-user static route, o - ODR

Gateway of last resort is not set

     137.20.0.0/24 is subnetted, 1 subnets
C 137.20.10.0 is directly connected, Ethernet2/0
     172.168.0.0/24 is subnetted, 1 subnets
C 172.168.70.0 is directly connected, Loopback0
r7#r
Building configuration...

Current configuration:
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname r7

!
interface Loopback0
 ip address 172.168.70.1 255.255.255.0
 no ip directed-broadcast
!

interface Ethernet2/0
 ip address 137.20.10.70 255.255.255.0
 no ip directed-broadcast

!
router bgp 3
 no synchronization
 network 172.168.0.0
 neighbor 200.200.100.1 remote-as 2
 neighbor 200.200.100.1 ebgp-multihop 2
 neighbor 200.200.100.1 route-map SET_MED out
 default-metric 170
!
ip local policy route-map bgp_ebgp
ip classless
!
access-list 100 permit ip any host 200.200.100.1 log
route-map bgp_ebgp permit 10
 match ip address 100
 set ip next-hop 137.20.10.1
!
route-map SET_MED permit 10
 set metric 170
!

r7#

Aaron DuShey



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