Unable to Connect two E-BGP Peers using IBGP Peers

[nishprit]

Hi I am a newbee to BGP. I have created a setup of IBGP and EBGP network a explained in the below attachments. Configuration also shared in the attachments on Router 1, 3, 4 and 6. Router 1 is able to learn Network 6.6.6.0 advertised by Router 6. Same is the case with Router 6 which is also learning Network 1.1.1.0 advertised by Router1. However when I am trying to ping 6.6.6.6 from Router 1 it is showing below output:

R1#ping 6.6.6.6

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 6.6.6.6, timeout is 2 seconds:
UUUUU
Success rate is 0 percent (0/5)

Same is the case when I am trying to ping 1.1.1.1 from Router 6.

Please let me know how to recetify this problem.

[nishprit]

Please find attached snaps

[MHM Cisco World]

In ibgp peer add 

Redistrubte connect 

Neighbor x.x.x.x next-hop-self

MHM

[MHM Cisco World]

This work without next-hop-self or redis??

MHM

[nishprit]

Hi it worked with full IBGP membership and next-hope-self. 

[MHM Cisco World]

So next-hop-self is add ? Just confirm

And for using source it sure work' I suggest use redistrubte connect under bgp to make all bgp peer know how to reply to ping.

MHM

[nishprit]

Hi @MHM Cisco World  I will sure try the steps as suggested. Once I finish learning redsitribute I will try and update you. Thanks for guidance.

[MHM Cisco World]

Sure' take your time.

Goodluck 

MHM

[Harold Ritter · Accepted solution]

Hi @nishprit ,

Since R1 and R6 only know about the loopback ip address of the other router, you should specify the lo0 ip address as the ping source address.

ping 6.6.6.6 source 1.1.1.1

Also make sure that all the routers in AS200 are meshed so that they all have a route to 1.1.1.0/24 and 6.6.6.0/24.

Regards, 

[nishprit]

HI @Harold Ritter As per your comments, I did full mesh IBGP peering as below:

R3 <-> R2, R3<->R4

R2<->R3, R2<->R4

R4<->R2, R4<->R3

Then I run update source loopback on R3 and R4 as peering was done through loopback. Then it work. Thanks for your solution. It was my first BGP set up.

[Harold Ritter]

You are very welcome @nishprit and thanks for the feedback

[paul driver]

Hello
Eigrp process < disable auto summarisation)
R2-5 - ibgp full mesh peering to each other
R3-6 nexthop-self to all other ibgp peers

test again

[Harold Ritter]

Hi @paul driver ,

> Eigrp process < disable auto summarisation)

The eigrp summarization doesn't prevent the BGP sessions to come up or proper forwarding through AS200.

> R2-5 - ibgp full mesh peering to each other

This is required as indicated in my previous post.

> R3-6 nexthop-self to all other ibgp peers

next-hop-self is not required in this scenario as the edge networks (192.168.1.0/24 and 192.168.2.0/24) are injected in the IGP.

Regards,

[paul driver]

Hello Harold
Thanks for the feedback, I agree with your comments mate- but it was  just a belt and braces approach, the assumption was the igp was populated correctly however its not shown hence the suggestion of next-hop-self and disablement eigrp summarization obviously along with full mesh iBGP which tbh I over-read your comments of that -  so apologies.

[Harold Ritter]

Hi @paul driver ,

I agree that adding these extra configurations would not hurt the connectivity between R1 and R6.

Regards,