09-23-2016 11:18 PM - edited 03-05-2019 07:08 AM
Hey guys,
I have a problem with this topology, I'm new to BGP so I'm trying to understand this.
(R1)
ip route 192.168.2.2 255.255.255.255 209.165.202.130
router bgp 65100
bgp log-neighbor-changes
network 209.165.200.224 mask 255.255.255.224
neighbor 192.168.2.2 remote-as 65000
neighbor 192.168.2.2 ebgp-multihop 255
neighbor 192.168.2.2 update-source Loopback0
(R2)
ip route 209.165.201.1 255.255.255.255 209.165.202.129
router bgp 65000
bgp log-neighbor-changes
network 192.168.22.0
neighbor 192.168.3.3 remote-as 65000
neighbor 192.168.3.3 update-source Loopback0
neighbor 192.168.3.3 next-hop-self
neighbor 209.165.201.1 remote-as 65100
neighbor 209.165.201.1 ebgp-multihop 255
neighbor 209.165.201.1 update-source Loopback0
(R3)
router bgp 65000
bgp log-neighbor-changes
network 192.168.33.0
neighbor 192.168.2.2 remote-as 65000
neighbor 192.168.2.2 update-source Loopback0
The thing I dont understand is that R1 and R2 can ping each other but R1 and R3 can't
Both R1 and R3 have entrees in the bgp table for each other but wont ping each other.
Can someone explain why?
Solved! Go to Solution.
09-24-2016 01:56 AM
Hello
I am checking you are missing some configuration as below
R2:
R3:
ip route 192.168.2.2 255.255.255.255 172.16.23.2
Why you are using the static route for your wan link. You should use the default route for WAN link on R2 router.
Don't worry, If you want to keep the same configuration as you did then use Source Loopback interface 1 during the ping command:
Example:
R1#ping 192.168.33.1 source loopback 1
Regards,
Deepak Kumar
www.deepuverma.in
09-24-2016 01:32 AM
Because you don't have route for R1 in R3 routing table similarly no route for R3 in R1 routing table
09-24-2016 11:24 AM
I did have routes for both, I did traceroute and it looks like it drops it at R2
09-24-2016 01:56 AM
Hello
I am checking you are missing some configuration as below
R2:
R3:
ip route 192.168.2.2 255.255.255.255 172.16.23.2
Why you are using the static route for your wan link. You should use the default route for WAN link on R2 router.
Don't worry, If you want to keep the same configuration as you did then use Source Loopback interface 1 during the ping command:
Example:
R1#ping 192.168.33.1 source loopback 1
Regards,
Deepak Kumar
www.deepuverma.in
09-24-2016 11:35 AM
Hello Deepak,
I'm running OSPF on R2 and R3 so no need for static routes.
R1#ping 192.168.33.1 source loopback 1 ... did actually work.
Can you explain why it doesnt work as ping 192.168.33.1 but when you use source loopback, it will actually ping, I guess that made me confused
09-24-2016 12:07 PM
Hi Deepak,
redistribute bgp into ospf on R2 that should fix the problem.
09-24-2016 11:46 PM
Dear Gaurav,
As I can understand, He is using OSPF or Static routing to communicate loopback interface with each other and BGP is another think.
Regards,
Deepak Kumar
www.deepuverma.in
09-24-2016 11:41 PM
Thanks for mark my answer as correct.
But you didn't mention in the question about OSPF configuration.
Regards,
Deepak Kumar
09-25-2016 12:30 AM
Yea sorry about that.
So can you explain why it doesn't work if you don't use "source loopback" when pinging?
09-25-2016 12:36 AM
HI
When you trying to ping without "Source Loopback" then ICMP packet come with "Source IP 209.165.202.129" but R3 does not have any information about IP 209.165.202.129 in its routing table so packet dropped when R3 will trying to make reply.
Regards,
Deepak Kumar
www.deepuverma.in
09-25-2016 01:12 AM
Ohh yea makes sense now.
Thanks a lot.
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