SIMULATION
Network topology exhibit
Domain .com recently issued a contract to ISP (AS 65020) to provide a second Internet connection their Boston location. A new router, Domain 3, will need to be configured to connect to the Internet Service Providers. It is necessary to configure this router to exchange routes with both ISPs, and to filter the routing advertisements out to the ISPs. The basic configuration for the new router has been entered. It is only necessary to complete the BGP configuration steps outlined below.
On the Domain 3 router:
Configure BGP to exchange routes with ISP-A (AS 65010). Configure BGP to exchange routes with ISP-B (AS 65020). Only announce the two local Ethernet LAN prefixes (172.16.1.0/24 and 172.16.2.0/24) to the ISPs.
Configure the appropriate as-path access-list to permit only locally originated routes to be advertised in outbound routing updates to the ISPs. Use as-patch ACL number 10 containing only one statement. Start the simulation by clicking on the local host icon.
A.
B.
C.
D.
Explanation:
To properly inject prefixes in a BGP routing table, it must exists in a IP routing table. network command and ip route with Null0 would announce a route to a BGP peers (ISP).
interface Fastethernet0/0
ip address 172.16.1.129 255.255.255.0
no shutdown
!
interface Fastethernet0/1
ip address 172.16.2.129 255.255.255.0
no shutdown
!
interface Serial0/0
ip address 10.20.20.5 255.255.255.252
no shutdown
!
interface Serial0/1
ip address 10.10.10.5 255.255.255.252
no shutdown
!
ip route 0.0.0.0 0.0.0.0 10.19.19.6
ip route 0.0.0.0 0.0.0.0 10.20.20.6
ip route 172.16.1.0 255.255.255.0 Null0
ip route 172.16.2.0 255.255.255.0 Null0
!
router bgp 65001
network 172.16.1.0 mask 255.255.255.0
network 172.16.2.0 mask 255.255.255.0
neighbor 10.10.10.6 remote-as 65010
neighbor 10.20.20.6 remote-as 65020
neighbor 10.10.10.6 filter-list 10 out
neighbor 10.20.20.6 fileer-list 10 out
no synchronization
no auto-summary
!
ip as-path access-list 10 permit ^$
!