Problem with OE2 redistribution from OSPF to BGP

[Dan22]

Hello,

The topology I want to discuss is as following.

On R4, two EIGRP route are redistributed in OSPF. Route 44.44.44.44 is tagged with 111.

So on R2, there are two OE2 routes.

I did below redistribution from OSPF to BGP on R2 with a route-map to filer out the tag 111.

router bgp 10001
bgp log-neighbor-changes
redistribute ospf 1 match external 1 external 2 route-map O2B
neighbor 192.168.12.1 remote-as 10000
route-map O2B deny 10
match tag 111
route-map O2B permit 20

The expectation is only 55.55.55.55/32 would be injected.

But it shows O routes are also injected to BGP. Below is the route table of R1.

May I ask why Intra OSPF routes are redistributed even there is no keyword "internal" in the redistribute command?

How to inject OE routes without tag?

Config files are attached as well.

Thanks a lot.

BR,
Dan

[Giuseppe Larosa]

Hello @Dan22 ,

>> May I ask why Intra OSPF routes are redistributed even there is no keyword "internal" in the redistribute command?

This is done by default.

Use a prefix-list to match route 55.55.55.55/32 and add match address prefix <prefix-list-name> to clause 20 of route-map O2B

Hope to help

Giuseppe

[Dan22]

Hello Giuseppe,

May I interpret it that if we redistribute with route-map, internal ospf route will be added implicitly?

Is it a design behavior of CISCO devise?

BR,
Dan

[Giuseppe Larosa · Accepted solution]

Hello @Dan22 ,

>>

May I interpret it that if we redistribute with route-map, internal ospf route will be added implicitly?

Is it a design behavior of CISCO devise?

yes we can say this.

As an alternative you could try to match on route-type within the route-map itself with match type . I have never tried this.

Hope to help

Giuseppe

[Dan22]

Giuseppe,

Understand.

Thanks a lot.

BR,

Dan