10-15-2008 02:50 AM - edited 03-03-2019 11:56 PM
Hello,
I am trying to redistribute BGP routes to OSPF. BGP and OSPF is running on PE router, OSPF only on CE router. Routers are connected via IP tunnel.
I have following configuration:
PE:
router ospf 120 vrf szdc_global
log-adjacency-changes
redistribute connected subnets
redistribute static subnets
redistribute bgp 64512 subnets
network 10.12.0.0 0.0.255.255 area 12
router bgp 64512
....
address-family ipv4 vrf szdc_global
redistribute connected
redistribute static
redistribute ospf 120 vrf szdc_global match internal external 1 external 2 nssa-external 1 nssa-external 2
default-information originate
bgp redistribute-internal
no auto-summary
no synchronization
exit-address-family
and on CE router:
router ospf 120 vrf szdc_global
log-adjacency-changes
redistribute connected subnets
redistribute static subnets
network 10.12.0.0 0.0.255.255 area 12
routing table of vrf szdc_global on PE router:
10.0.0.0/8 is variably subnetted, 8 subnets, 3 masks
C 10.12.254.222/32 is directly connected, Loopback5
B 10.16.254.201/32 [200/0] via 10.251.254.16, 4d23h
B 10.80.254.200/32 [200/0] via 10.251.254.80, 4d22h
B 10.80.251.32/30 [200/0] via 10.251.254.80, 4d22h
B 10.80.200.0/24 [200/110] via 10.251.254.80, 03:54:03
C 10.12.251.92/30 is directly connected, Tunnel10
C 10.12.194.0/24 is directly connected, GigabitEthernet0/1.194
B 10.12.193.0/24 is directly connected, 4d23h, GigabitEthernet0/1.193
S* 0.0.0.0/0 [1/0] via 10.12.194.2
and on CE router:
10.0.0.0/8 is variably subnetted, 4 subnets, 3 masks
O 10.12.254.222/32 [110/11112] via 10.12.251.93, 01:17:06, Tunnel0
O E2 10.16.254.201/32 [110/1] via 10.12.251.93, 01:17:06, Tunnel0
C 10.12.251.92/30 is directly connected, Tunnel0
O 10.12.194.0/24 [110/11112] via 10.12.251.93, 01:17:06, Tunnel0
How is it possible, that 10.16.254.201/32 is redistributed, and 10.80.254.200/32 (for example) is not? Can't see the diffrence.
Thanks in advance,
Martin
10-15-2008 03:06 AM
u can use prefix list wirh route-map to deny what ever subnet/prefix to be redistributed
then use this route map in the redistribution command for example
ip prefix-list list1 seq 10 permit 10.80.254.200/32
route-map bgp-ospf deny 10
match ip address prefix-list list1
route-map bgp-ospf permit 20
redistribute bgp 64512 subnets route-map bgp-ospf
note: the second route map with sequence number 20 important because first one deny the match traffic the second one permit all other
and u can put what ever prefixes u want
good luck
if helpful Rate
10-15-2008 03:16 AM
Yeah, sure, I can use route-maps to filter prefixes, which I need to redistribute. But if I don't use any route-map, all prefixes should be redistributed by default...? Or am I mistaken here?
10-15-2008 07:47 AM
Hello Martin,
first of all I would try to change the redistribute command within AF ipv4 vrf szdc_global.
I would change it to:
redistribute ospf 120 vrf szdc_global
(actually in my IOS was only red ospf 120 there was a change in syntax for supporting up to 32 ospf processes for each VRF :
http://www.cisco.com/en/US/docs/ios/12_3t/12_3t4/feature/guide/gtospfvf.html)
and then on CE
router ospf 120 vrf szdc_global
capability vrf-lite
see the notes below and the link
Second note:
if you have other VRF sites using the OSPF as PE-CE link you are probably using different OSPF process-ids in different PE routers because I see the imported prefix as O E2 instead of O IA.
In my tests and in documents the OSPF area between PE and CE is area 0 so to let the PE build the "superbackbone area"
another difference I used O E1 routes:
red bgp 16232 metric-type 1 subnets
To compare the two prefixes 10.16.254.201/32 and 10.12.254.200/32 do the following on PE :
show ip bgp vpvn4 all 10.12.254.200
show ip bgp vpvn4 all 10.12.254.201
and
sh ip route vrf szdc_global 10.12.254.200
sh ip route vrf szdc_global 10.12.254.201
check to see if there is the following sentence imagine the changes for your scenario:
Routing entry for 172.16.60.11/32
Known via "bgp 16232", distance 200, metric 2, type internal
Redistributing via ospf 6762
>> Advertised by ospf 6762 metric-type 1 subnets
the key word is advertised.
If it is missing for the prefix not redistributed you need to find out why it is so because there are no route-filters
I just see that there are also examples using an area different from 0 between Pe-CE so this is not a valid argument.
If you are using a MultiVRF CE you may need:
router ospf 120 vrf szdc_global
capability vrf-lite
as explained in:
http://www.cisco.com/en/US/docs/ios/12_0st/12_0st21/feature/guide/ospfvrfl.html#wp1038874
Hope to help
Giuseppe
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