BGP同步实验
Platform:Dynamips(ccnp.net)
Step 1:基本配置
R1++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
int lo 0
ip add 1.1.1.1 255.255.255.255
int f0/0
no sh
int f0/0.12
en do 12
ip add 12.1.1.1 255.255.255.0
router ospf 100
router-id 1.1.1.1
network 0.0.0.0 0.0.0.0 area 0
router bgp 123
no synchronization
bgp router-id 1.1.1.1
bgp log-neighbor-changes
network 1.1.1.1 mask 255.255.255.255
neighbor 2.2.2.2 remote-as 123
neighbor 2.2.2.2 update-source Loopback0
neighbor 3.3.3.3 remote-as 123
neighbor 3.3.3.3 update-source Loopback0
no auto-summary
R2++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
interface Loopback0
ip address 2.2.2.2 255.255.255.255
!
interface FastEthernet0/0
no shutdown
!
interface FastEthernet0/0.12
encapsulation dot1Q 12
ip address 12.1.1.2 255.255.255.0
!
interface FastEthernet0/0.23
encapsulation dot1Q 23
ip address 23.1.1.2 255.255.255.0
router ospf 100
router-id 2.2.2.2
log-adjacency-changes
network 0.0.0.0 255.255.255.255 area 0
!
router bgp 123
no synchronization
bgp router-id 2.2.2.2
bgp log-neighbor-changes
neighbor 1.1.1.1 remote-as 123
neighbor 1.1.1.1 update-source Loopback0
neighbor 3.3.3.3 remote-as 123
neighbor 3.3.3.3 update-source Loopback0
no auto-summary
R3+++++++++++++++++++++++++++++++++++++++++++++++++++++
int lo 0
ip add 3.3.3.3 255.255.255.255
int f0/0
no sh
int f0/0.23
en do 23
ip add 23.1.1.3 255.255.255.0
int f0/0.34
en do 34
ip add 34.1.1.3 255.255.255.0
router ospf 100
router-id 3.3.3.3
log-adjacency-changes
network 3.3.3.3 0.0.0.0 area 0
network 23.1.1.0 0.0.0.255 area 0
!
router bgp 123
no synchronization
bgp router-id 3.3.3.3
bgp log-neighbor-changes
neighbor 1.1.1.1 remote-as 123
neighbor 1.1.1.1 update-source Loopback0
neighbor 1.1.1.1 next-hop-self
neighbor 2.2.2.2 remote-as 123
neighbor 2.2.2.2 update-source Loopback0
neighbor 2.2.2.2 next-hop-self
neighbor 34.1.1.4 remote-as 4
no auto-summary
R4++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
int lo 0
ip add 4.4.4.4 255.255.255.255
int f0/0.34
en do 34
ip add 34.1.1.4 255.255.255.0
int f0/0
no sh
router bgp 4
no synchronization
bgp router-id 4.4.4.4
bgp log-neighbor-changes
network 4.4.4.4 mask 255.255.255.255
neighbor 34.1.1.3 remote-as 123
no auto-summary
Step 2:test
在R1上ping 4.4.4.4 so lo 0
正常
当在R1上的BGP进程里开启同步功能。就出现以下现象。
R1#sh ip bgp
BGP table version is 2, local router ID is 1.1.1.1
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
*> 1.1.1.1/32 0.0.0.0 0 32768 i
* i4.4.4.4/32 3.3.3.3 0 100 0 4 i
4.4.4.4 无法最优
同步的意思是指当路由在IGP和BGP上同时存在，才能最优。
解决办法，在R1上写一条静态路由，做测试。
ip route 4.4.4.4 255.255.255.255 12.1.1.2
ping 4.4.4.4 so lo 0
