r1
hostname r1 ! interface GigabitEthernet1 no shutdown ip address 12.1.1.1 255.255.255.0
r2
hostname r2 ! interface GigabitEthernet1 no shutdown ip address 12.1.1.2 255.255.255.0 ! interface GigabitEthernet2 no shutdown ip address 23.1.1.2 255.255.255.0
r3
hostname r3 ! interface GigabitEthernet1 no shutdown ip address 34.1.1.3 255.255.255.0 ! interface GigabitEthernet2 no shutdown ip address 23.1.1.3 255.255.255.0
r4
hostname r4 ! interface GigabitEthernet1 no shutdown ip address 34.1.1.4 255.255.255.0
r1
interface Loopback0 ip address 1.1.1.1 255.255.255.255
r2
interface Loopback0 ip address 2.2.2.2 255.255.255.255
r3
interface Loopback0 ip address 3.3.3.3 255.255.255.255
r4
interface Loopback0 ip address 4.4.4.4 255.255.255.255
r2
router ospf 1 router-id 2.2.2.2 network 2.2.2.2 0.0.0.0 area 0 network 23.1.1.2 0.0.0.0 area 0
r3
router ospf 1 router-id 3.3.3.3 network 3.3.3.3 0.0.0.0 area 0 network 23.1.1.3 0.0.0.0 area 0
r1
router ospf 1 router-id 1.1.1.1 network 1.1.1.1 0.0.0.0 area 1 network 12.1.1.1 0.0.0.0 area 1
r2
router ospf 1 network 12.1.1.2 0.0.0.0 area 1
r3
router ospf 1 network 34.1.1.3 0.0.0.0 area 2
r4
router ospf 1 router-id 4.4.4.4 network 4.4.4.4 0.0.0.0 area 2 network 34.1.1.4 0.0.0.0 area 2
r1
r1#show ip ospf database topology | b Summary
Summary Net Link States (Area 1)
Link ID ADV Router Age Seq# Checksum
2.2.2.2 2.2.2.2 476 0x80000003 0x00F633
3.3.3.3 2.2.2.2 476 0x80000003 0x00D252
4.4.4.4 2.2.2.2 476 0x80000003 0x00AE71
23.1.1.0 2.2.2.2 717 0x80000007 0x00080D
34.1.1.0 2.2.2.2 476 0x80000007 0x008286
r2
r2#show ip ospf database topology | b Summary
Summary Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
1.1.1.1 2.2.2.2 755 0x80000003 0x002FFD
4.4.4.4 3.3.3.3 595 0x80000003 0x008696
12.1.1.0 2.2.2.2 755 0x80000003 0x009F84
34.1.1.0 3.3.3.3 595 0x80000005 0x005EA9
Router Link States (Area 1)
Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 561 0x8000000E 0x00C326 2
2.2.2.2 2.2.2.2 755 0x8000000D 0x007184 1
Net Link States (Area 1)
Link ID ADV Router Age Seq# Checksum
12.1.1.2 2.2.2.2 755 0x80000003 0x000E06
Summary Net Link States (Area 1)
Link ID ADV Router Age Seq# Checksum
2.2.2.2 2.2.2.2 514 0x80000003 0x00F633
3.3.3.3 2.2.2.2 514 0x80000003 0x00D252
4.4.4.4 2.2.2.2 514 0x80000003 0x00AE71
23.1.1.0 2.2.2.2 755 0x80000007 0x00080D
34.1.1.0 2.2.2.2 514 0x80000007 0x008286
r3
r3#show ip ospf database topology | b Summary
Summary Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
1.1.1.1 2.2.2.2 756 0x80000003 0x002FFD
4.4.4.4 3.3.3.3 594 0x80000003 0x008696
12.1.1.0 2.2.2.2 756 0x80000003 0x009F84
34.1.1.0 3.3.3.3 594 0x80000005 0x005EA9
Router Link States (Area 2)
Link ID ADV Router Age Seq# Checksum Link count
3.3.3.3 3.3.3.3 594 0x80000005 0x00E4E1 1
4.4.4.4 4.4.4.4 338 0x80000006 0x006F2D 2
Net Link States (Area 2)
Link ID ADV Router Age Seq# Checksum
34.1.1.4 4.4.4.4 338 0x80000003 0x00479C
Summary Net Link States (Area 2)
Link ID ADV Router Age Seq# Checksum
1.1.1.1 3.3.3.3 594 0x80000003 0x001B0D
2.2.2.2 3.3.3.3 594 0x80000003 0x00E242
3.3.3.3 3.3.3.3 594 0x80000003 0x00AA77
12.1.1.0 3.3.3.3 594 0x80000003 0x008B93
23.1.1.0 3.3.3.3 594 0x80000003 0x00F123
r4
r4#show ip ospf database topology | b Summary
Summary Net Link States (Area 2)
Link ID ADV Router Age Seq# Checksum
1.1.1.1 3.3.3.3 595 0x80000003 0x001B0D
2.2.2.2 3.3.3.3 595 0x80000003 0x00E242
3.3.3.3 3.3.3.3 595 0x80000003 0x00AA77
12.1.1.0 3.3.3.3 595 0x80000003 0x008B93
23.1.1.0 3.3.3.3 595 0x80000003 0x00F123
r1
r1#ping 1.1.1.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms r1#ping 2.2.2.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/3 ms r1#ping 3.3.3.3 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/3 ms r1#ping 4.4.4.4 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 4.4.4.4, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 2/2/3 ms r1#ping 12.1.1.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 12.1.1.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms r1#ping 12.1.1.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 12.1.1.2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms r1#ping 23.1.1.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 23.1.1.2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms r1#ping 23.1.1.3 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 23.1.1.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms r1#ping 34.1.1.3 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 34.1.1.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/3 ms r1#ping 34.1.1.4 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 34.1.1.4, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/3 ms
r2
r2#ping 1.1.1.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms r2#ping 2.2.2.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/8 ms r2#ping 3.3.3.3 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms r2#ping 4.4.4.4 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 4.4.4.4, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/3 ms r2#ping 12.1.1.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 12.1.1.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms r2#ping 12.1.1.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 12.1.1.2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms r2#ping 23.1.1.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 23.1.1.2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms r2#ping 23.1.1.3 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 23.1.1.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms r2#ping 34.1.1.3 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 34.1.1.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms r2#ping 34.1.1.4 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 34.1.1.4, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms
r3
r3#ping 1.1.1.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/3 ms r3#ping 2.2.2.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms r3#ping 3.3.3.3 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms r3#ping 4.4.4.4 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 4.4.4.4, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms r3#ping 12.1.1.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 12.1.1.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms r3#ping 12.1.1.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 12.1.1.2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms r3#ping 23.1.1.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 23.1.1.2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms r3#ping 23.1.1.3 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 23.1.1.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms r3#ping 34.1.1.3 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 34.1.1.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms r3#ping 34.1.1.4 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 34.1.1.4, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
r4
r4#ping 1.1.1.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms r4#ping 2.2.2.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms r4#ping 3.3.3.3 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms r4#ping 4.4.4.4 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 4.4.4.4, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms r4#ping 12.1.1.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 12.1.1.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 2/2/3 ms r4#ping 12.1.1.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 12.1.1.2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms r4#ping 23.1.1.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 23.1.1.2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/3 ms r4#ping 23.1.1.3 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 23.1.1.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms r4#ping 34.1.1.3 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 34.1.1.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms r4#ping 34.1.1.4 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 34.1.1.4, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
r1
router bgp 65000 bgp router-id 1.1.1.1
r4
router bgp 65001 bgp router-id 4.4.4.4
r1
router bgp 65000 neighbor 4.4.4.4 remote-as 65001 neighbor 4.4.4.4 ebgp-multihop 3 neighbor 4.4.4.4 update-source Loopback0
r4
router bgp 65001 neighbor 1.1.1.1 remote-as 65000 neighbor 1.1.1.1 ebgp-multihop 3 neighbor 1.1.1.1 update-source Loopback0
r1
r1#show ip bgp nei | i BGP neighbor is|BGP state BGP neighbor is 4.4.4.4, remote AS 65001, external link BGP state = Established, up for 01:11:12
r4
r4#show ip bgp nei | i BGP neighbor is|BGP state BGP neighbor is 1.1.1.1, remote AS 65000, external link BGP state = Established, up for 01:11:12