From: Roberts, Larry (Larry.Roberts@expanets.com)
Date: Sat Sep 21 2002 - 13:40:32 GMT-3
OK,
after reviewing the document I believe that it is either missing some very
key information, or this document deals with older version of codes.
Case in point.
I have 3 routers running both OSPF and BGP. On 2 of them I am redistributing
OSPF into BGP with only the redistribute OSPF 100 command.
On the 3rd, I see all those routes in BGP. Now, per the document you MUST
add the match parameter, but I don't have it on either of them.
And the 3rd router is learning ALL my internal routers ( several hundred )
via BGP.
I do however use the same AS on all 3 internal routers. Could that be the
difference ?
I am running 12.0(9)and 12.0(10) on the redistributing routers and 12.0(13)
on the receiving BGP router.
Here is the config of one of those routers..
router bgp 64575
no synchronization
network 10.21.1.0 mask 255.255.255.0
network 10.36.48.1 mask 255.255.254.0
network 10.39.255.236 mask 255.255.255.252
network 10.39.255.240 mask 255.255.255.252
redistribute static route-map STATICREDIS
redistribute ospf 100
neighbor 10.39.255.238 remote-as 64575
neighbor 10.39.255.242 remote-as 64575
distance bgp 115 200 1
no auto-summary
Any thoughts ????
Thanks
Larry
-----Original Message-----
From: Rich West [mailto:westrk102002@yahoo.com]
Sent: Saturday, September 21, 2002 10:46 AM
To: Hunt Lee; ccielab@groupstudy.com
Subject: Redistributing BGP into OSPF
There is a gotcha when redistributing BGP into OSPF. You must use the
command 'bgp redistribute-internal' under your BGP AS. Since you normally
don't redistribute BGP into an IGP, this is a little safety valve. Hope
this works for you. -Rich
Hunt Lee wrote:Hello,
When redistributing OSPF into BGP, I know that one needs to use the "match"
keyword:-
http://www.cisco.com/warp/public/104/bgp-ospf-redis.html
But today, when I tried to do the other way round, by redistributing BGP
into OSPF. I tried everything but I couldn't get the BGP route to be
redistributed into OSPF. Is there any rules or gotcha about redistributing
BGP routes into OSPF?
RTA --- RTB ----- RTC --- 3.3.3.3/32
IBGP
The network 3.3.3.3/32 is advertised into the network by BGP's network
command at RTC. Both RTB & RTC have used the "no synch" command. RTA & RTB
are OSPF Area 0, and RTB is the ASBR (redistributing BGP routes into OSPF).
RouterB#sh ip route
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, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
1.0.0.0/32 is subnetted, 1 subnets
O IA 1.1.1.1 [110/65] via 10.1.1.1, 00:03:24, Serial1 2.0.0.0/32 is
subnetted, 1 subnets C 2.2.2.2 is directly connected, Loopback0 3.0.0.0/32
is subnetted, 1 subnets B 3.3.3.3 [200/0] via 10.1.1.6, 00:00:27 10.0.0.0/30
is subnetted, 2 subnets C 10.1.1.0 is directly connected, Serial1 C 10.1.1.4
is directly connected, Serial0 RouterB#sh ip bgp BGP table version is 2,
local router ID is 2.2.2.2 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
*>i3.3.3.3/32 10.1.1.6 0 100 0 i
RouterB#ping 3.3.3.3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds: !!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/31/32 ms
RouterB#
As illustrated above, I can see the BGP route 3.3.3.3/32 fine at RTB's
Routing Table & BGP table. But I just couldn't redistribute this BGP route
into OSPF.
At RTB:
router ospf 2
log-adjacency-changes
redistribute bgp 2 subnets
passive-interface Serial0
network 2.2.2.2 0.0.0.0 area 2
network 10.1.1.0 0.0.0.3 area 0
!
router bgp 2
no synchronization
bgp log-neighbor-changes
neighbor 10.1.1.6 remote-as 2
RouterB#sh ip ospf database
OSPF Router with ID (2.2.2.2) (Process ID 2)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link
count
1.1.1.1 1.1.1.1 166 0x80000004 0x6A10 2
2.2.2.2 2.2.2.2 199 0x80000006 0xC65 2
Summary Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
1.1.1.1 1.1.1.1 166 0x80000003 0x43EE
2.2.2.2 2.2.2.2 199 0x80000003 0xF633
Router Link States (Area 2)
Link ID ADV Router Age Seq# Checksum Link
count
2.2.2.2 2.2.2.2 199 0x80000003 0xAB69 1
Summary Net Link States (Area 2)
Link ID ADV Router Age Seq# Checksum
1.1.1.1 2.2.2.2 199 0x80000003 0xA746
10.1.1.0 2.2.2.2 200 0x80000003 0x20C9
RouterB#
Hence, I can't see the 3.3.3.3/32 route at RTA's Routing Table.
RouterA>sh ip route
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, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
1.0.0.0/32 is subnetted, 1 subnets
C 1.1.1.1 is directly connected, Loopback0
2.0.0.0/32 is subnetted, 1 subnets
O IA 2.2.2.2 [110/65] via 10.1.1.2, 00:08:12, Serial0 10.0.0.0/30 is
subnetted, 1 subnets C 10.1.1.0 is directly connected, Serial0
RouterA>
It would be greatly appreciated if anyone can shed some light onto this.
Best Regards,
L.
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This archive was generated by hypermail 2.1.4 : Mon Oct 07 2002 - 07:43:59 GMT-3