BGP邻居的形成
R1------(-R2--------R3--------R4-)==============R5（一条串口，一条以太口）
AS10 OSPF AS20 AS 30
R1#show ip interface brief
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 unassigned YES unset administratively down down
Serial1/0 unassigned YES unset administratively down down
Serial1/1 10.10.12.1 YES manual up up
Serial1/2 unassigned YES unset administratively down down
Serial1/3 unassigned YES unset administratively down down
Loopback0 1.1.1.1 YES manual up up
Loopback10 172.16.10.1 YES manual up up
R2#show ip interface brief
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 unassigned YES unset administratively down down
Serial1/0 10.10.12.2 YES manual up up
Serial1/1 10.10.23.2 YES manual up up
Serial1/2 unassigned YES unset administratively down down
Serial1/3 unassigned YES unset administratively down down
Loopback0 2.2.2.2 YES manual up up
R2#show ip interface brief
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 unassigned YES unset administratively down down
Serial1/0 10.10.12.2 YES manual up up
Serial1/1 10.10.23.2 YES manual up up
Serial1/2 unassigned YES unset administratively down down
Serial1/3 unassigned YES unset administratively down down
Loopback0 2.2.2.2 YES manual up up
R1:
router bgp 10
no synchronization
bgp router-id 1.1.1.1
bgp log-neighbor-changes
network 1.1.1.1 mask 255.255.255.255
network 172.16.10.1 mask 255.255.255.255
neighbor 10.10.12.2 remote-as 20
neighbor 10.10.12.2 ebgp-multihop 255
no auto-summary
R2:
router ospf 1
log-adjacency-changes
network 2.2.2.2 0.0.0.0 area 0
network 10.10.23.0 0.0.0.255 area 0
!
router bgp 20
no synchronization
bgp log-neighbor-changes
network 2.2.2.2 mask 255.255.255.255
neighbor 3.3.3.3 remote-as 20
neighbor 3.3.3.3 update-source Loopback0
neighbor 3.3.3.3 next-hop-self
neighbor 4.4.4.4 remote-as 20
neighbor 4.4.4.4 update-source Loopback0
neighbor 4.4.4.4 next-hop-self
neighbor 10.10.12.1 remote-as 10
neighbor 10.10.12.1 ebgp-multihop 255
no auto-summary
R3:
R3#show run | begin router
router ospf 1
log-adjacency-changes
network 3.3.3.3 0.0.0.0 area 0
network 10.10.23.0 0.0.0.255 area 0
network 10.10.34.0 0.0.0.255 area 0
!
router bgp 20
no synchronization
bgp log-neighbor-changes
network 3.3.3.3 mask 255.255.255.255
neighbor 2.2.2.2 remote-as 20
neighbor 2.2.2.2 update-source Loopback0
neighbor 4.4.4.4 remote-as 20
neighbor 4.4.4.4 update-source Loopback0
no auto-summary
!
R4:
router ospf 1
log-adjacency-changes
network 4.4.4.4 0.0.0.0 area 0
network 10.10.34.0 0.0.0.255 area 0
!
router bgp 20
no synchronization
bgp log-neighbor-changes
network 192.168.45.0
neighbor 2.2.2.2 remote-as 20
neighbor 2.2.2.2 update-source Loopback0
neighbor 2.2.2.2 next-hop-self
neighbor 3.3.3.3 remote-as 20
neighbor 3.3.3.3 update-source Loopback0
neighbor 3.3.3.3 next-hop-self
neighbor 5.5.5.5 remote-as 30
neighbor 5.5.5.5 ebgp-multihop 255
neighbor 5.5.5.5 update-source Loopback0
no auto-summary
!
ip classless
ip route 5.5.5.5 255.255.255.255 10.10.45.5
ip route 5.5.5.5 255.255.255.255 192.168.45.5
ip http server
!
!
R5:
R5#show run | begin router
router bgp 30
no synchronization
bgp log-neighbor-changes
network 5.5.5.5 mask 255.255.255.255
neighbor 4.4.4.4 remote-as 20
neighbor 4.4.4.4 ebgp-multihop 255
neighbor 4.4.4.4 update-source Loopback0
no auto-summary
!
ip classless
ip route 4.4.4.4 255.255.255.255 192.168.45.4
ip route 4.4.4.4 255.255.255.255 10.10.45.4
R1#show ip bgp summary
BGP router identifier 1.1.1.1, local AS number 10
BGP table version is 7, main routing table version 7
6 network entries using 582 bytes of memory
6 path entries using 216 bytes of memory
4 BGP path attribute entries using 240 bytes of memory
2 BGP AS-PATH entries using 48 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 1086 total bytes of memory
BGP activity 15/9 prefixes, 17/11 paths, scan interval 60 secs
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
10.10.12.2 4 20 102 92 7 0 0 00:13:32 4
R2#show ip bgp summary
BGP router identifier 2.2.2.2, local AS number 20
BGP table version is 13, main routing table version 13
6 network entries using 582 bytes of memory
6 path entries using 216 bytes of memory
4 BGP path attribute entries using 240 bytes of memory
2 BGP AS-PATH entries using 48 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 1086 total bytes of memory
BGP activity 15/9 prefixes, 16/10 paths, scan interval 60 secs
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
3.3.3.3 4 20 109 125 13 0 0 00:20:15 1
4.4.4.4 4 20 128 136 13 0 0 00:17:27 2
10.10.12.1 4 10 93 103 13 0 0 00:14:01 2
R3#show ip bgp summary
BGP router identifier 3.3.3.3, local AS number 20
BGP table version is 13, main routing table version 13
6 network entries using 582 bytes of memory
6 path entries using 216 bytes of memory
4 BGP path attribute entries using 240 bytes of memory
2 BGP AS-PATH entries using 48 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 1086 total bytes of memory
BGP activity 12/6 prefixes, 17/11 paths, scan interval 60 secs
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
2.2.2.2 4 20 125 109 13 0 0 00:20:42 3
4.4.4.4 4 20 117 102 13 0 0 00:17:54 2
R4#show ip bgp summary
BGP router identifier 4.4.4.4, local AS number 20
BGP table version is 9, main routing table version 9
6 network entries using 582 bytes of memory
6 path entries using 216 bytes of memory
4 BGP path attribute entries using 240 bytes of memory
2 BGP AS-PATH entries using 48 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 1086 total bytes of memory
BGP activity 16/10 prefixes, 17/11 paths, scan interval 60 secs
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
2.2.2.2 4 20 137 129 9 0 0 00:18:18 3
3.3.3.3 4 20 103 118 9 0 0 00:18:18 1
5.5.5.5 4 30 77 89 9 0 0 00:18:08 1
R5#show ip bgp summary
BGP router identifier 5.5.5.5, local AS number 30
BGP table version is 21, main routing table version 21
6 network entries using 582 bytes of memory
6 path entries using 216 bytes of memory
4 BGP path attribute entries using 240 bytes of memory
2 BGP AS-PATH entries using 48 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 1086 total bytes of memory
BGP activity 12/6 prefixes, 13/7 paths, scan interval 60 secs
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
4.4.4.4 4 20 89 77 21 0 0 00:18:29 5
R1#show ip bgp
BGP table version is 7, local router ID is 1.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 1.1.1.1/32 0.0.0.0 0 32768 i
*> 2.2.2.2/32 10.10.12.2 0 0 20 i
*> 3.3.3.3/32 10.10.12.2 0 20 i
*> 5.5.5.5/32 10.10.12.2 0 20 30 i
*> 172.16.10.1/32 0.0.0.0 0 32768 i
R2#show ip bgp
Network Next Hop Metric LocPrf Weight Path
*> 1.1.1.1/32 10.10.12.1 0 0 10 i
*> 2.2.2.2/32 0.0.0.0 0 32768 i
*>i3.3.3.3/32 3.3.3.3 0 100 0 i
*>i5.5.5.5/32 4.4.4.4 0 100 0 30 i
*> 172.16.10.1/32 10.10.12.1 0 0 10 i
*>i192.168.45.0 4.4.4.4 0 100 0 i
R3#show ip bgp
Network Next Hop Metric LocPrf Weight Path
*>i1.1.1.1/32 2.2.2.2 0 100 0 10 i
*>i2.2.2.2/32 2.2.2.2 0 100 0 i
*> 3.3.3.3/32 0.0.0.0 0 32768 i
*>i5.5.5.5/32 4.4.4.4 0 100 0 30 i
*>i172.16.10.1/32 2.2.2.2 0 100 0 10 i
*>i192.168.45.0 4.4.4.4 0 100 0 i
R4#show ip bgp
Network Next Hop Metric LocPrf Weight Path
*>i1.1.1.1/32 2.2.2.2 0 100 0 10 i
*>i2.2.2.2/32 2.2.2.2 0 100 0 i
*>i3.3.3.3/32 3.3.3.3 0 100 0 i
*> 5.5.5.5/32 5.5.5.5 0 0 30 i
*>i172.16.10.1/32 2.2.2.2 0 100 0 10 i
*> 192.168.45.0 0.0.0.0 0 32768 i
R5#show ip bgp
Network Next Hop Metric LocPrf Weight Path
*> 1.1.1.1/32 4.4.4.4 0 20 10 i
*> 2.2.2.2/32 4.4.4.4 0 20 i
*> 3.3.3.3/32 4.4.4.4 0 20 i
*> 5.5.5.5/32 0.0.0.0 0 32768 i
*> 172.16.10.1/32 4.4.4.4 0 20 10 i
*> 192.168.45.0 4.4.4.4 0 0 20 i
欢迎大家指正错误，学习交流！！！
