4byte as number and redistribution between OSPF and BGP

[mothukuri]

Hi Experts ,

We have SVis configured on Nexus 7718 switches , which are part of area 0 and fabripath is running between them. We are running OSPF as IGP and We have EGBP with Palo alto Firewall.

whenever we are redistributing ospf into bgp and vice-versa we are not getting ospf routes into BGP and bgp routes into OSPF.

we are using 4byet AS numbers ie 10.1 , 10.2 and 10.200 and also we are using community list.

nexus 7k config :

interface Vlan19
no shutdown
no ip redirects
ip address 10.10.10.2/24
no ipv6 redirects
ip ospf passive-interface
ip router ospf 20 area 0.0.0.0
hsrp 19
ip 10.10.10.1

interface Vlan20
no shutdown
no ip redirects
ip address 20.10.10.2/24
no ipv6 redirects
ip ospf passive-interface
ip router ospf 20 area 0.0.0.0
hsrp 20
ip 20.10.10.1

router ospf 20
router-id 10.147.0.120

redistribute bgp 10.1 route-map bgp_in_ospf

router bgp 10.1
router-id 60.60.60.1
address-family ipv4 unicast
redistribute ospf 20 route-map ospf_in_bgp
neighbor 40.40.40.1 remote-as 10.1
update-source loopback35
timers 10 30
address-family ipv4 unicast
soft-reconfiguration inbound
neighbor 50.50.50.1 remote-as 10.200
local-as 10.3 no-prepend replace-as dual-as
timers 30 90
address-family ipv4 unicast
next-hop-self
soft-reconfiguration inbound

route-map bgp_in_ospf deny 10
match community bgp_redis
route-map bgp_in_ospf permit 20
set tag 200
set metric-type type-1

route-map ospf_in_bgp deny 10
match tag 200
route-map ospf_in_bgp permit 20
set extcommunity 4byteas-generic transitive 10.3:99

ip extcommunity-list standard bgp_redis 4bytegeneric  transitive 10.3:99

IBGP is fine between nexus 7ks  & EBGP is formed with Palo alto FW .main problem is that OSPF routes are not getting redistributed into BGP and vice-versa.

Could you please check above config and confirm whether extcommunity works in this case as we are using dotted AS numbers.

[M02@rt37]

Hello @mothukuri 

On Nexus interfaces vlan 19 and 20 you have both 'ip ospf passive-interface' and  'ip router ospf 20 area 0.0.0.0'

ip ospf passive-interface command prevents OSPF hello packets from being sent on the specified interface, effectively disabling OSPF neighbor adjacencies on that interface. On the other hand, ip router ospf 20 area 0.0.0.0 command enables OSPF on the specified interface and includes it in the specified OSPF area.... 

Remove 'ip ospf passive-interface' command.

[mothukuri]

Hello , ospf is fine and I've point to point ospf link between nexus7ks. My question is intra area routes of ospf are not visible in bgp . Whatever route maps and extcommunity configured , is it correct ? I have AS number without dotted decimal in another data center and I do not see any problem with redistribution. Any example of ospf to bgp and bgp to ospf rediribution with dotted AS (10.1 , 10.2 )number helps me a lot 

[MHM Cisco World]

redistribute ospf 20 route-map ospf_in_bgp match internal external 1 external 2

Check this.