Lab 136 - BGP Peer Groups

Lab 136 - BGP Peer Groups
Di Posting Oleh : Simple Learning
Kategori : BGP Core Technologies Routing

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Disclaimer

The author of the posts will not assume any liability or responsibility to any person or entity with respect to loss or damages incurred from information contained in this blog. Any resemblance to some other training materials and/or CCIE exam is completely coincidental.
Full information:
http://hackingcisco.blogspot.com/2011/01/cisco-going-pro.html

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Prerequisites: CCNP level skills.

Note!

I have created a pdf document with OSPF Lab 1 and 2 containing a detailed lab breakdown. Check it out if want. Any feedback is most welcome.

http://www.4shared.com/document/W8lhDzNo/Hacking-Cisco-OSPF-Lab1-2-Brea.html

Topology

Pic. 1 - Topology Diagram.

 

Icons designed by: Andrzej Szoblik - http://www.newo.pl

Task 1

R3 in AS 123 is going to peer with few hundred routers running iBGP session and you will need to save its resources (CPU). Configure R3 iBGP peering in such a way that it checks the routing table only once and replicates the same update to all its iBGP peers.

Solution

Task 1

R3 in AS 123 is going to peer with few hundred routers running iBGP session and you will need to save its resources (CPU). Configure R3 iBGP peering in such a way that it checks the routing table only once and replicates the same update to all its iBGP peers.
R3 Configuration:

!

router bgp 123
 no synchronization
 bgp router-id 172.16.103.3
 bgp log-neighbor-changes
 network 172.16.103.0 mask 255.255.255.0
 neighbor IBGP_ROUTERS peer-group
 neighbor IBGP_ROUTERS remote-as 123
 neighbor IBGP_ROUTERS route-reflector-client
 neighbor IBGP_ROUTERS next-hop-self
 neighbor 10.1.13.1 peer-group IBGP_ROUTERS
 neighbor 10.1.23.2 peer-group IBGP_ROUTERS
 neighbor 10.1.35.5 remote-as 50
 no auto-summary

!

Verification:

Pic. 2 - BGP Peer Group.

Pic. 3 - BGP Peer Group Members Summary.

Note!
BGP Peer groups have limitations:

• All neighbors that shared the same peer group configuration also had to share the same outbound routing policies.
• All neighbors had to belong to the same peer group and address family. Neighbors configured in different address-families could not belong to different peer groups.

Source:
http://www.cisco.com/en/US/docs/ios/12_0s/feature/guide/s_bgpct.html#wp1027184

(The second bullet point tries to underline the fact that you cannot mix iBGP and eBGP peers in the same peer group).

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