NULL 0
Step 5: Configure EBGP
Configure ISP to run EBGP with SanJose1 and SanJose2. Enter the following
commands on ISP:
ISP(config)#router bgp 200
ISP(config-router)#neighbor 192.168.1.6 remote-as 64512
ISP(config-router)#neighbor 192.168.1.2 remote-as 64512
ISP(config-router)#network 192.168.100.0
Step 6: Verify BGP Neighbors
Configure SanJose1 as an EBGP peer to ISP:
SanJose1(config)#ip route 172.16.0.0 255.255.0.0 null0
SanJose1(config)#router bgp 64512
SanJose1(config-router)#neighbor 192.168.1.5 remote-as 200
SanJose1(config-router)#network 172.16.0.0
Step 7: View BGP Summary Output
Configure SanJose2 as an EBGP peer to ISP:
SanJose2(config)#ip route 172.16.0.0 255.255.0.0 null0
SanJose2(config)#router bgp 64512
SanJose2(config-router)#neighbor 192.168.1.1 remote-as 200
SanJose2(config-router)#network 172.16.0.0
i could not understand the job of static route null 0 here could someone take a look and explain plz
Configure ISP to run EBGP with SanJose1 and SanJose2. Enter the following
commands on ISP:
ISP(config)#router bgp 200
ISP(config-router)#neighbor 192.168.1.6 remote-as 64512
ISP(config-router)#neighbor 192.168.1.2 remote-as 64512
ISP(config-router)#network 192.168.100.0
Step 6: Verify BGP Neighbors
Configure SanJose1 as an EBGP peer to ISP:
SanJose1(config)#ip route 172.16.0.0 255.255.0.0 null0
SanJose1(config)#router bgp 64512
SanJose1(config-router)#neighbor 192.168.1.5 remote-as 200
SanJose1(config-router)#network 172.16.0.0
Step 7: View BGP Summary Output
Configure SanJose2 as an EBGP peer to ISP:
SanJose2(config)#ip route 172.16.0.0 255.255.0.0 null0
SanJose2(config)#router bgp 64512
SanJose2(config-router)#neighbor 192.168.1.1 remote-as 200
SanJose2(config-router)#network 172.16.0.0
i could not understand the job of static route null 0 here could someone take a look and explain plz
Comments
http://www.cisco.com/en/US/tech/tk364/technologies_tech_note09186a00801c9a6e.shtml
The static route is used to place the supernet route in the routing table so BGP will advertise it to the other AS as the supernet.
Sorry if this doesn't make sense but still figuring it out myself. If anyone could explain this a little better I would appreciate a deeper understanding.
Thanks.
An alternitive to this type of configuration is to use the aggragate address command to advertise an aggregate to the BGP peers.