Configuring Interfaces IP address for IGP and BGP
ISP
interface FastEthernet0/0 ip address 121.121.121.1 255.255.255.252 interface FastEthernet0/1 ip address 122.122.122.1 255.255.255.252
A1
interface Loopback1 ip address 100.100.100.1 255.255.255.255 interface FastEthernet0/0 ip address 192.168.100.1 255.255.255.0 interface FastEthernet0/1 ip address 121.121.121.2 255.255.255.252
A2
interface Loopback1 ip address 100.100.100.2 255.255.255.255 interface FastEthernet0/0 ip address 192.168.100.2 255.255.255.0
B1
interface Loopback1 ip address 200.200.200.1 255.255.255.255 interface FastEthernet0/0 ip address 192.168.200.1 255.255.255.0 interface FastEthernet0/1 ip address 122.122.122.2 255.255.255.252
B2
interface Loopback1 ip address 200.200.200.2 255.255.255.255 interface FastEthernet0/0 ip address 192.168.200.2 255.255.255.0
B3
interface Loopback1 ip address 200.200.200.3 255.255.255.255 interface FastEthernet0/0 ip address 192.168.200.3 255.255.255.0
Configuring IGP in AS 100 and AS 200 and verify peers/routes
AS100 (EIGRP)
A1(config)#router eigrp 100
A1(config-router)#network 100.100.100.1 0.0.0.0
A1(config-router)#network 192.168.100.1 0.0.0.0
A1(config-router)#no auto-summary
A2(config)#router eigrp 100
A2(config-router)#network 100.100.100.2 0.0.0.0
A2(config-router)#network 192.168.100.2 0.0.0.0
A2(config-router)#no auto-summary
A1#sh ip eigrp neighbors
IP-EIGRP neighbors for process 100
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
0 192.168.100.2 Fa0/0 13 00:01:38 20 200 0 9
A1#sh ip route eigrp
100.0.0.0/32 is subnetted, 2 subnets
D 100.100.100.2 [90/409600] via 192.168.100.2, 00:00:15, FastEthernet0/0
A2#sh ip eigrp neighbors
IP-EIGRP neighbors for process 100
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
0 192.168.100.1 Fa0/0 14 00:02:00 432 2592 0 10
A2#sh ip route eigrp
100.0.0.0/32 is subnetted, 2 subnets
D 100.100.100.1 [90/409600] via 192.168.100.1, 00:00:56, FastEthernet0/0
AS200 (OSPF)
B1(config)#router ospf 1 B1(config-router)#router-id 200.200.200.1 B1(config-router)#network 200.200.200.1 0.0.0.0 are 0 B1(config-router)#network 192.168.200.1 0.0.0.0 are 0
B2(config)#router ospf 1 B2(config-router)#router-id 200.200.200.2 B2(config-router)#network 200.200.200.2 0.0.0.0 are 0 B2(config-router)#network 192.168.200.2 0.0.0.0 are 0
B3(config)#router ospf 1 B3(config-router)#router-id 200.200.200.3 B3(config-router)#network 200.200.200.3 0.0.0.0 are 0 B3(config-router)#network 192.168.200.3 0.0.0.0 are 0
B1#sh ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 200.200.200.2 1 FULL/BDR 00:00:34 192.168.200.2 FastEthernet0/0 200.200.200.3 1 FULL/DROTHER 00:00:37 192.168.200.3 FastEthernet0/0 B1#sh ip route ospf 200.200.200.0/32 is subnetted, 3 subnets O 200.200.200.2 [110/11] via 192.168.200.2, 00:01:46, FastEthernet0/0 O 200.200.200.3 [110/11] via 192.168.200.3, 00:01:06, FastEthernet0/0 B2#sh ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 200.200.200.1 1 FULL/DR 00:00:38 192.168.200.1 FastEthernet0/0 200.200.200.3 1 FULL/DROTHER 00:00:30 192.168.200.3 FastEthernet0/0 B2#sh ip route ospf 200.200.200.0/32 is subnetted, 3 subnets O 200.200.200.1 [110/11] via 192.168.200.1, 00:01:59, FastEthernet0/0 O 200.200.200.3 [110/11] via 192.168.200.3, 00:01:19, FastEthernet0/0 B3#sh ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 200.200.200.1 1 FULL/DR 00:00:35 192.168.200.1 FastEthernet0/0 200.200.200.2 1 FULL/BDR 00:00:34 192.168.200.2 FastEthernet0/0 B3#sh ip route ospf 200.200.200.0/32 is subnetted, 3 subnets O 200.200.200.1 [110/11] via 192.168.200.1, 00:01:51, FastEthernet0/0 O 200.200.200.2 [110/11] via 192.168.200.2, 00:01:51, FastEthernet0/0
Configuring EBGP between ISP and AS 100, AS 200
ISP(config)#int l1 ISP(config-if)#ip add 120.120.120.120 255.255.255.255 ISP(config)#router bgp 120 ISP(config-router)#bgp router-id 120.120.120.120 ISP(config-router)#neighbor 121.121.121.2 remote-as 100
ISP(config-router)#neighbor 122.122.122.2 remote-as 200 ISP(config-router)#network 120.120.120.120 mask 255.255.255.255 A1(config)#router bgp 100 A1(config-router)#bgp router-id 100.100.100.1 A1(config-router)#neighbor 121.121.121.1 remote-as 120 B1(config)#router bgp 200 B1(config-router)#bgp router-id 200.200.200.1 B1(config-router)#neighbor 122.122.122.1 remote-as 120 ISP#sh ip bgp summary | B Nei Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 121.121.121.2 4 100 14 16 2 0 0 00:02:46 0 122.122.122.2 4 200 5 6 2 0 0 00:01:05 0 A1#sh ip bgp su | b Nei Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 121.121.121.1 4 120 17 15 2 0 0 00:03:10 1 B1#sh ip bgp su | b Nei Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 122.122.122.1 4 120 6 5 2 0 0 00:01:49 1
Configuring iBGP in AS 100 and AS 200
A1(config)#router bgp 100 A1(config-router)#neighbor 192.168.100.2 remote-as 100 A1(config-router)#neighbor 192.168.100.2 next-hop-self
A2(config)#router bgp 100 A2(config-router)#bgp router-id 100.100.100.2 A2(config-router)#neighbor 192.168.100.1 remote-as 100 A2(config-router)#neighbor 192.168.100.1 next-hop-self
A1#sh ip bgp summary | b Nei Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 121.121.121.1 4 120 69 67 2 0 0 00:55:21 1 192.168.100.2 4 100 4 5 2 0 0 00:00:45 0 A2#sh ip bgp summary | b Nei Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 192.168.100.1 4 100 5 4 2 0 0 00:00:50 1 B1(config)#router bgp 200 B1(config-router)#neighbor 192.168.200.2 remote-as 200 B1(config-router)#neighbor 192.168.200.2 next-hop-self B1(config-router)#neighbor 192.168.200.2 route-reflector-client B1(config-router)# B1(config-router)#neighbor 192.168.200.3 remote-as 200 B1(config-router)#neighbor 192.168.200.3 next-hop-self B1(config-router)#neighbor 192.168.200.3 route-reflector-client B2(config)#router bgp 200 B2(config-router)#bgp router-id 200.200.200.2 B2(config-router)#neighbor 192.168.200.1 remote-as 200 B2(config-router)#neighbor 192.168.200.1 next-hop-self B3(config)#router bgp 200 B3(config-router)#bgp router-id 200.200.200.3 B3(config-router)#neighbor 192.168.200.1 remote-as 200 B3(config-router)#neighbor 192.168.200.1 next-hop-self B1#sh ip bgp su | b Nei Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 122.122.122.1 4 120 62 61 2 0 0 00:57:34 1 192.168.200.2 4 200 5 6 2 0 0 00:01:29 0 192.168.200.3 4 200 4 5 2 0 0 00:00:33 0 B3#sh ip bgp summary | b Nei Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 192.168.200.1 4 200 5 4 2 0 0 00:00:51 1 B2#sh ip bgp summary | b Nei Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 192.168.200.1 4 200 7 6 2 0 0 00:02:04 1
Advertise Public IP range to ISP and verify routing test between AS100 and 200
A1(config)#router bgp 100 A1(config-router)#network 100.100.100.0 mask 255.255.255.0 A1(config-router)#exit A1(config)# A1(config)#ip route 100.100.100.0 255.255.255.0 null 0 B1(config)#router bgp 200 B1(config-router)#network 200.200.200.0 mask 255.255.255.0 B1(config-router)#exit B1(config)# B1(config)#ip route 200.200.200.0 255.255.255.0 null 0 ISP#sh ip bgp su | b Nei Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 121.121.121.2 4 100 75 78 4 0 0 01:02:50 1 122.122.122.2 4 200 66 68 4 0 0 01:01:10 1 ISP#sh ip bgp BGP table version is 4, local router ID is 120.120.120.120 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 100.100.100.0/24 121.121.121.2 0 0 100 i *> 120.120.120.120/32 0.0.0.0 0 32768 i *> 200.200.200.0 122.122.122.2 0 0 200 i A2#sh ip bgp BGP table version is 4, local router ID is 100.100.100.2 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP,? - incomplete Network Next Hop Metric LocPrf Weight Path *>i100.100.100.0/24 192.168.100.1 0 100 0 i *>i120.120.120.120/32 192.168.100.1 0 100 0 120 i *>i200.200.200.0 192.168.100.1 0 100 0 120 200 i B3#sh ip bgp BGP table version is 4, local router ID is 200.200.200.3 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP,? - incomplete Network Next Hop Metric LocPrf Weight Path *>i100.100.100.0/24 192.168.200.1 0 100 0 120 100 i *>i120.120.120.120/32 192.168.200.1 0 100 0 120 i *>i200.200.200.0 192.168.200.1 0 100 0 i A2#ping 200.200.200.3 source 100.100.100.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echosto 200.200.200.3, timeout is 2 seconds: Packet sent with a sourceaddress of 100.100.100.2 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 40/49/56 ms B3#ping 100.100.100.2 source 200.200.200.3 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 100.100.100.2, timeout is 2 seconds: Packet sent with a source address of 200.200.200.3 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 40/56/68 ms