BGP newbie question

Answered Question
May 24th, 2007
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I have two routers R1 --- R2, both running OSPF, both in full adjacency.

If I configure BGP in both routers, and configure redistribute static in R1, then R2 should see those static routers, correct? Why am I not seeing those routes?

R1 config:

router bgp 64674

synchronization

bgp log-neighbor-changes

redistribute static

no auto-summary


R2 config:

router bgp 64674

synchronization

bgp log-neighbor-changes

no auto-summary


R1 has this static route:

Network Next Hop Metric LocPrf Weight Path

*> 10.197.0.0/16 172.31.6.10 0 32768 ?


But R2 is not seeing it. Why?

Correct Answer by Harold Ritter about 10 years 1 month ago

Sarah,


For BGP routers to connect and start exchanging routing information, you need to configure neighbor statements under BGP.


R1:

router bgp 64674

neighbor x.x.x.x remote-as 64674


R2:

router bgp 64674

neighbor y.y.y.y remote-as 64674


where x.x.x.x is R2 interface address and y.y.y.y is R1 interface address.


It is also possible to establishing using the loopback interface, in which case you would have:


R1:

neighbor x.x.x.x remote-as 64674

neighbor x.x.x.x update-source looback 0


where x.x.x is the loopback interface address on R2.


Hope this helps,

Correct Answer by bjornarsb about 10 years 1 month ago

Hi,


Nice going!

You just need to add the neighour statement :)

router bgp 64674

neighbour XXXX remote-as 64674

...



Check the scroll-bar at the bottom rigth of every helpfull post :)


BR,

Bjornarsb

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Correct Answer
bjornarsb Thu, 05/24/2007 - 09:50
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  • Bronze, 100 points or more

Hi,


Nice going!

You just need to add the neighour statement :)

router bgp 64674

neighbour XXXX remote-as 64674

...



Check the scroll-bar at the bottom rigth of every helpfull post :)


BR,

Bjornarsb

bjornarsb Thu, 05/24/2007 - 09:51
User Badges:
  • Bronze, 100 points or more

and so you know bgp differ from ospf and eigrp and ... bgp do not use multicast 224.x.x.x it uses tcp port 179 :)

Harold Ritter Thu, 05/24/2007 - 09:57
User Badges:
  • Cisco Employee,

Sarah,


For BGP routers to connect and start exchanging routing information, you need to configure neighbor statements under BGP.


R1:

router bgp 64674

neighbor x.x.x.x remote-as 64674


R2:

router bgp 64674

neighbor y.y.y.y remote-as 64674


where x.x.x.x is R2 interface address and y.y.y.y is R1 interface address.


It is also possible to establishing using the loopback interface, in which case you would have:


R1:

neighbor x.x.x.x remote-as 64674

neighbor x.x.x.x update-source looback 0


where x.x.x is the loopback interface address on R2.


Hope this helps,

sarah12345 Thu, 05/24/2007 - 10:00
User Badges:

Man, you guys are quick. Thanks!


It seems unlike OSPF, I have to specify the interface IP as the neighbor IP? If I specify the loopback address of the neighbor router, it doesn't know how to get to it?

Correct Answer
Harold Ritter Thu, 05/24/2007 - 10:01
User Badges:
  • Cisco Employee,

Sarah,


For BGP routers to connect and start exchanging routing information, you need to configure neighbor statements under BGP.


R1:

router bgp 64674

neighbor x.x.x.x remote-as 64674


R2:

router bgp 64674

neighbor y.y.y.y remote-as 64674


where x.x.x.x is R2 interface address and y.y.y.y is R1 interface address.


It is also possible to establishing using the loopback interface, in which case you would have:


R1:

neighbor x.x.x.x remote-as 64674

neighbor x.x.x.x update-source looback 0


where x.x.x is the loopback interface address on R2.


Hope this helps,

sarah12345 Thu, 05/24/2007 - 10:10
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I got it working now with both iface IP and loopback address. Thanks a lot!

Harold Ritter Thu, 05/24/2007 - 10:16
User Badges:
  • Cisco Employee,

Great. Sorry for the double posting. I must have hit one too many key.


Regards,

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