08-19-2006 09:58 AM - edited 03-03-2019 01:42 PM
Gents,
I have here a connected route, redistributed into OSPF, that is not making it into BGP. Any ideas as to why?
R8#sh ip ospf database external 150.50.4.0
OSPF Router with ID (200.0.0.8) (Process ID 1)
Type-5 AS External Link States
LS age: 1232
Options: (No TOS-capability, DC)
LS Type: AS External Link
Link State ID: 150.x.4.0 (External Network Number )
Advertising Router: 200.0.0.8
LS Seq Number: 80000001
Checksum: 0x7C86
Length: 36
Network Mask: /24
Metric Type: 2 (Larger than any link state path)
TOS: 0
Metric: 20
Forward Address: 0.0.0.0
External Route Tag: 0
R8#
R8 Config :
router bgp 65078
no synchronization
bgp log-neighbor-changes
bgp confederation identifier 200
bgp confederation peers 65256
redistribute ospf 1 match internal external 1 external 2
neighbor 150.x.5.68 remote-as 65078
neighbor 150.x.5.68 next-hop-self
no auto-summary
But no cigar:
R8#sh ip bgp
BGP table version is 3, local router ID is 200.0.0.8
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 8.8.8.0/24 0.0.0.0 0 32768 ?
*> 150.50.5.64/27 0.0.0.0 0 32768 ?
R8#
IOS version:
R8#sh ver
Cisco IOS Software, 2800 Software (C2800NM-ADVENTERPRISEK9-M), Version 12.4(3a), RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2005 by Cisco Systems, Inc.
Compiled Fri 30-Sep-05 13:24 by hqluong
Configuration:
R8#sh run
Building configuration...
Current configuration : 1704 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
!
hostname R8
!
boot-start-marker
boot-end-marker
!
enable secret xxx
!
no aaa new-model
!
resource policy
!
memory-size iomem 15
ip subnet-zero
!
!
ip cef
!
!
no ip domain lookup
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface Loopback0
ip address 200.0.x.x.255.255.255
!
interface Loopback1
ip address 8.8.x.x.255.255.0
ip ospf network point-to-point
!
interface FastEthernet0/0
ip address 150.x.4.x.255.255.0
duplex auto
speed auto
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/0/0
ip address 150.x.5.x.255.255.224
!
router ospf 1
log-adjacency-changes
redistribute connected subnets route-map Conn
network 8.8.8.1 0.0.0.0 area 0
network 150.x.5.x.0.0.0 area 0
!
router bgp 65078
no synchronization
bgp log-neighbor-changes
bgp confederation identifier 200
bgp confederation peers 65256
redistribute ospf 1 match internal external 1 external 2
neighbor 150.50.5.68 remote-as 65078
neighbor 150.x.5.68 next-hop-self
no auto-summary
!
ip classless
!
!
no ip http server
no ip http secure-server
!
access-list 1 permit 150.x.4.x.0.0.255
!
route-map Conn permit 10
match ip address 1
!
!
!
!
control-plane
!
!
!
!
!
!
!
!
!
banner motd ^CC Blah, Blah, Blah... If you are not an authorized user, go away!!! ^C
alias configure sir show ip route
alias configure siib show ip interface brief
!
line con 0
exec-timeout 0 0
password 7 121015120A1B09163E
logging synchronous
line aux 0
line vty 0 4
login
!
warm-reboot
scheduler allocate 20000 1000
!
end
Solved! Go to Solution.
08-19-2006 10:46 AM
Marcel
There are several possible causes. I think that the first one to consider is that the route that you are interested in is a connected route. If you enter the command show ip route and look for the prefix 150.50.4.0 it shows up as a connected route ("C") not OSPF External ("O E2"). When BGP redistributes routes it will be looking in the routing table for routes with an O indicator not a C indicator.
One way to fix this would be to change the BGP config so that it redistributes connected instead of redistributing OSPF. If you use the same route map to control redistribution you would get just the single connected route. Another potential fix is to put a network statement into OSPF for 150.50.4.0 and let it become an OSPF internal route. And perhaps the solution that I would favor would be to put a network statement into BGP for that prefix instead of trying to redistribute.
HTH
Rick
08-19-2006 10:46 AM
Marcel
There are several possible causes. I think that the first one to consider is that the route that you are interested in is a connected route. If you enter the command show ip route and look for the prefix 150.50.4.0 it shows up as a connected route ("C") not OSPF External ("O E2"). When BGP redistributes routes it will be looking in the routing table for routes with an O indicator not a C indicator.
One way to fix this would be to change the BGP config so that it redistributes connected instead of redistributing OSPF. If you use the same route map to control redistribution you would get just the single connected route. Another potential fix is to put a network statement into OSPF for 150.50.4.0 and let it become an OSPF internal route. And perhaps the solution that I would favor would be to put a network statement into BGP for that prefix instead of trying to redistribute.
HTH
Rick
08-19-2006 10:57 AM
Hi Rick,
thanks for your quick response. Clear and insightful as always.
I now realize the error of my ways and you are spot on. The specific solution does not matter, it's understanding the mechanism which is what I was after. And you explained it perfectly.
Cheers,
Marcel
08-19-2006 11:02 AM
Marcel
Thank you for rating the post and marking that it did solve your question. It makes the forum more useful when people can read a question and know that an answer was provided which solved it.
And I certainly agree with you that understanding the principles involved is more important that the particular details. And redistribution can be a tricky thing to understand.
HTH
Rick
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