eBGP connection

[imstha001]

Hi all,

We have customer and they wants connection with us from one of our point of presence.They want to run eBGP on their own.I have attached the network diagram.

1.As shown in diagram RTR-I and RTR-II are  border router and we are running eBGP and accepting entire internet routing table.

2.We are running iBGP between RTR-I and RTR-II

3.Client want connection from one of Access Router Cisco 2911-C

In that case we need to run iBGP from RTR-I,RTR-III,Cisco2911-A,cisco 2911-B and Cisco 2911-C.The problem is other routers can not hold the entire routing table.

Now please suggest me if there is any simple way to have eBGP connection to Client (RTR-x).I am think of to have GRE tunnel between RTR-I and Cisco 2911-C.Will this work? If there any better way to do it please suggest me.

Thanks

[Deepak Kumar]

Hi,

As I can understand your question, you are facing problem related to BGP full-mesh. You need to BGP router reflector in IBGP network. 

As example below:

https://networklessons.com/bgp/bgp-route-reflector/

Regards,

Deepak Kumar

[imstha001]

Thanks Deepak.

[Georg Pauwen]

Hello,

you could still use eBGP on the customer router RTR-x if you configure an inbound AS_PATH filter list on that router. Since I don't know the AS numbers you are using, I cannot give you the exact syntax of the filter list, but take a look at the configuration example below to give you an idea.

By the way, receiving the full BGP routing table occupies approximately 70MB of memory (which can be handled by a 2911). After applying the inbound filter, memory usage is cut to about 30MB.

What routing protocol are you currently running between RTR-III and Cisco2911-C ?

http://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/12512-41.html

[imstha001]

Thanks

We are using OSPF as IGP.

My issue is I just can not run iBGP in all those routers with full routing table.We are accepting  full routing table in RTR-I and RTR-II.

I might need to summarize the routing table or I am not sure if we can announce default route to iBGP.

and other option is running iBGP over GRE tunnel between RTR-I and Cisco 2911-C.

Kindly let me know if there is any better option

[paul driver]

Hello

Would Is this client be using you for all its routing if so why would you need BGP?

I am assuming Cisco 2911-C has reachability to both transits , If so why not just connect this client  to Cisco 2911-C and provide some statc routing

Make it simple as possible.

res
Paul

[imstha001]

Thanks Paul

Client has own AS number  with IP block.

They want to multi homing the network with different provider.