BGP routing

[Chin]

Hi Guys,

I have a doubt on ip route which advertise by BGP.

When I show ip route and the specified ip route not showing. Is it the subnet in the ip prefix and ip route must be tally? Wish anyone can pinpoint where was the wrong config i did. 

Here is my config:

ip route 172.16.100.0 255.255.255.0 172.16.145.1

ip prefix-list ROUTE-WAN seq 5 permit 172.16.100.0/29

router bgp 60500

no synchronization

bgp log-neighbor-changes

network 172.16.0.0

timers bgp 15 20

redistribute connected

redistribute static

neighbor XX.XX.XX.XX remote-as 4747

neighbor XX.XX.XX.XX route-map BGP-WAN out

no auto-summary

route-map BGP-WAN permit 10

match ip address prefix-list ROUTE-WAN

[bjornarsb · Accepted solution]

Hi,

Try changing the mask in the prefix-list to /24

hth

[Chin]

Hi Bjornarsb,

I have change the ip router to 172.168.100.0/29 and the BGP able to advertised it.

Thank you very much.

[Muhammad Thanveer]

can you please share the output for

sh bgp ipv4 uni summ

sh bp ipv4 uni

You have the ip route command is in which router.

I mean do you have /29 of 172.16.100.0 is local to your router and you also have some other network other than /29 in other routers.

Regards
Thanveer
"Everybody is genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is a stupid."

[Muhammad Thanveer · Accepted solution]

Hello,

If the above mentioned is the case, then I have tested it and found problem with

ip route 172.16.100.0 255.255.255.0 172.16.145.1 command

if you are doing a static route for the /29 route excluding the one which is locally orginating, there would be no problem.

Regards
Thanveer
"Everybody is genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is a stupid."

[Chin]

Hi Muhammad,

Sorry for late reply, Yup, I change the ip route

ip route 172.16.100.0 255.255.255.240 172.16.145.1 and BGP able to advertised the network segment.

Thanks for your help.

[Bilal Nawaz]

Hello, BGP considers the /24 and the /29 as totally different routes, therefor you will always need a specific match. BGP criteria for advertisement is that the exact prefix should be present in the routing table to be advertised out. And rightly suggested above the correct commands for this.

You also had 'redistribute static' - did you see the /24 being advertised out?

You wouldn't need the 'neighbor XX.XX.XX.XX route-map BGP-WAN out' command if you are redistributing your statics.

Hope this helps.

Please rate useful posts and remember to mark any solved questions as answered. Thank you.

[Chin]

Hi Bilal Nawaz,

Thanks for your explanation. After I sorted it out the /24 to /29, it is able to advertised out.

"You wouldn't need the 'neighbor XX.XX.XX.XX route-map BGP-WAN out' command if you are redistributing your statics."

Yup, I found this command also unnecessary to put in BGP config as well.