解決BGP中IBGP的路由黑洞

R1與R2間EBGP,R4與R5間EBGP,R2與R4間IBGP,但因爲R3學不到相關的路由,形成路由黑洞。處理的方法主要如下幾個:redis

如下是路由器配置:ide

R1:oop

interface Loopback0
 ip address 1.1.1.1 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.1 255.255.255.252
!
router bgp 100
 bgp log-neighbor-changes
 network 1.1.1.1 mask 255.255.255.255
 neighbor 192.168.1.2 remote-as 200router

R5:ip

interface Loopback0
 ip address 5.5.5.5 255.255.255.255
!
interface FastEthernet0/1
 ip address 192.168.1.14 255.255.255.252
 speed auto
 duplex auto
!
router bgp 300
 bgp log-neighbor-changes
 network 5.5.5.5 mask 255.255.255.255
 neighbor 192.168.1.13 remote-as 200路由

一、IBGP全鏈接rem

R2:io

interface Loopback0
 ip address 2.2.2.2 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.5 255.255.255.252
!
interface FastEthernet0/1
 ip address 192.168.1.2 255.255.255.252
!
router ospf 1
 router-id 2.2.2.2
 network 2.2.2.2 0.0.0.0 area 0
 network 192.168.1.4 0.0.0.3 area 0
!
router bgp 200
 bgp log-neighbor-changes
 neighbor 3.3.3.3 remote-as 200
 neighbor 3.3.3.3 update-source Loopback0
 neighbor 3.3.3.3 next-hop-self
 neighbor 4.4.4.4 remote-as 200
 neighbor 4.4.4.4 update-source Loopback0
 neighbor 4.4.4.4 next-hop-self
 neighbor 192.168.1.1 remote-as 100ast

R3:cli

interface Loopback0
 ip address 3.3.3.3 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.9 255.255.255.252
!
interface FastEthernet0/1
 ip address 192.168.1.6 255.255.255.252
!
router ospf 1
 router-id 3.3.3.3
 network 3.3.3.3 0.0.0.0 area 0
 network 192.168.1.4 0.0.0.3 area 0
 network 192.168.1.8 0.0.0.3 area 0
!
router bgp 200
 bgp log-neighbor-changes
 neighbor 2.2.2.2 remote-as 200
 neighbor 2.2.2.2 update-source Loopback0
 neighbor 2.2.2.2 next-hop-self
 neighbor 4.4.4.4 remote-as 200
 neighbor 4.4.4.4 update-source Loopback0
 neighbor 4.4.4.4 next-hop-self

R4:

interface Loopback0
 ip address 4.4.4.4 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.13 255.255.255.252
!
interface FastEthernet0/1
 ip address 192.168.1.10 255.255.255.252
!
router ospf 1
 router-id 4.4.4.4
 network 4.4.4.4 0.0.0.0 area 0
 network 192.168.1.8 0.0.0.3 area 0
!
router bgp 200
 bgp log-neighbor-changes
 neighbor 2.2.2.2 remote-as 200
 neighbor 2.2.2.2 update-source Loopback0
 neighbor 2.2.2.2 next-hop-self
 neighbor 3.3.3.3 remote-as 200
 neighbor 3.3.3.3 update-source Loopback0
 neighbor 3.3.3.3 next-hop-self
 neighbor 192.168.1.14 remote-as 300

二、路由反射器

R2:

interface Loopback0
 ip address 2.2.2.2 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.5 255.255.255.252
!
interface FastEthernet0/1
 ip address 192.168.1.2 255.255.255.252
!
router ospf 1
 router-id 2.2.2.2
 network 2.2.2.2 0.0.0.0 area 0
 network 192.168.1.4 0.0.0.3 area 0
!
router bgp 200
 bgp log-neighbor-changes
 neighbor 3.3.3.3 remote-as 200
 neighbor 3.3.3.3 update-source Loopback0
 neighbor 3.3.3.3 next-hop-self
 neighbor 192.168.1.1 remote-as 100

R3:

interface Loopback0
 ip address 3.3.3.3 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.9 255.255.255.252
!
interface FastEthernet0/1
 ip address 192.168.1.6 255.255.255.252
!
router ospf 1
 router-id 3.3.3.3
 network 3.3.3.3 0.0.0.0 area 0
 network 192.168.1.4 0.0.0.3 area 0
 network 192.168.1.8 0.0.0.3 area 0
!
router bgp 200
 bgp log-neighbor-changes
 neighbor 2.2.2.2 remote-as 200
 neighbor 2.2.2.2 update-source Loopback0
 neighbor 2.2.2.2 route-reflector-client
 neighbor 4.4.4.4 remote-as 200
 neighbor 4.4.4.4 update-source Loopback0
 neighbor 4.4.4.4 route-reflector-client

R4:

interface Loopback0
 ip address 4.4.4.4 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.13 255.255.255.252
!
interface FastEthernet0/1
 ip address 192.168.1.10 255.255.255.252
!
router ospf 1
 router-id 4.4.4.4
 network 4.4.4.4 0.0.0.0 area 0
 network 192.168.1.8 0.0.0.3 area 0
!
router bgp 200
 bgp log-neighbor-changes
 neighbor 3.3.3.3 remote-as 200
 neighbor 3.3.3.3 update-source Loopback0
 neighbor 3.3.3.3 next-hop-self
 neighbor 192.168.1.14 remote-as 300

三、BGP邦連

R2:

interface Loopback0
 ip address 2.2.2.2 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.5 255.255.255.252
!
interface FastEthernet0/1
 ip address 192.168.1.2 255.255.255.252
!
router ospf 1
 router-id 2.2.2.2
 network 2.2.2.2 0.0.0.0 area 0
 network 192.168.1.4 0.0.0.3 area 0
!
router bgp 65530
 bgp router-id 2.2.2.2
 bgp log-neighbor-changes
 bgp confederation identifier 200
 bgp confederation peers 65531
 neighbor 3.3.3.3 remote-as 65531

 neighbor 3.3.3.3 ebgp-multihop 255
 neighbor 3.3.3.3 update-source Loopback0
 neighbor 3.3.3.3 next-hop-self
 neighbor 192.168.1.1 remote-as 100

R3:

interface Loopback0
 ip address 3.3.3.3 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.9 255.255.255.252
!
interface FastEthernet0/1
 ip address 192.168.1.6 255.255.255.252
!
router ospf 1
 router-id 3.3.3.3
 network 3.3.3.3 0.0.0.0 area 0
 network 192.168.1.4 0.0.0.3 area 0
 network 192.168.1.8 0.0.0.3 area 0
!
router bgp 65531
 bgp router-id 3.3.3.3
 bgp log-neighbor-changes
 bgp confederation identifier 200
 bgp confederation peers 65530 65532
 neighbor 2.2.2.2 remote-as 65530

 neighbor 2.2.2.2 ebgp-multihop 255
 neighbor 2.2.2.2 update-source Loopback0
 neighbor 2.2.2.2 next-hop-self
 neighbor 4.4.4.4 remote-as 65532
 neighbor 4.4.4.4 ebgp-multihop 255
 neighbor 4.4.4.4 update-source Loopback0
 neighbor 4.4.4.4 next-hop-self

R4:

interface Loopback0
 ip address 4.4.4.4 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.13 255.255.255.252
 speed auto
 duplex auto
!
interface FastEthernet0/1
 ip address 192.168.1.10 255.255.255.252
!
router ospf 1
 router-id 4.4.4.4
 network 4.4.4.4 0.0.0.0 area 0
 network 192.168.1.8 0.0.0.3 area 0
!
router bgp 65532
 bgp log-neighbor-changes
 bgp confederation identifier 200
 bgp confederation peers 65531
 neighbor 3.3.3.3 remote-as 65531

 neighbor 3.3.3.3 ebgp-multihop 255
 neighbor 3.3.3.3 update-source Loopback0
 neighbor 3.3.3.3 next-hop-self
 neighbor 192.168.1.14 remote-as 300

四、配置MPLS

R2:

interface Loopback0
 ip address 2.2.2.2 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.5 255.255.255.252
 mpls ip
!
interface FastEthernet0/1
 ip address 192.168.1.2 255.255.255.252
!
router ospf 1
 router-id 2.2.2.2
 network 2.2.2.2 0.0.0.0 area 0
 network 192.168.1.4 0.0.0.3 area 0
!
router bgp 200
 bgp log-neighbor-changes
 neighbor 4.4.4.4 remote-as 200
 neighbor 4.4.4.4 update-source Loopback0
 neighbor 4.4.4.4 next-hop-self
 neighbor 192.168.1.1 remote-as 100
R3:

interface Loopback0
 ip address 3.3.3.3 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.9 255.255.255.252
 mpls ip
!
interface FastEthernet0/1
 ip address 192.168.1.6 255.255.255.252
 mpls ip
!
router ospf 1
 router-id 3.3.3.3
 network 3.3.3.3 0.0.0.0 area 0
 network 192.168.1.4 0.0.0.3 area 0
 network 192.168.1.8 0.0.0.3 area 0


R4:

interface Loopback0
 ip address 4.4.4.4 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.13 255.255.255.252
!
interface FastEthernet0/1
 ip address 192.168.1.10 255.255.255.252
 mpls ip
!
router ospf 1
 router-id 4.4.4.4
 network 4.4.4.4 0.0.0.0 area 0
 network 192.168.1.8 0.0.0.3 area 0
!
router bgp 200
 bgp log-neighbor-changes
 neighbor 2.2.2.2 remote-as 200
 neighbor 2.2.2.2 update-source Loopback0
 neighbor 2.2.2.2 next-hop-self
 neighbor 192.168.1.14 remote-as 300
 

五、BGP路由重分發到IGP(不建議)

R2:

interface Loopback0
 ip address 2.2.2.2 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.5 255.255.255.252
!
interface FastEthernet0/1
 ip address 192.168.1.2 255.255.255.252
!
router ospf 1
 router-id 2.2.2.2
 redistribute bgp 200 subnets
 network 2.2.2.2 0.0.0.0 area 0
 network 192.168.1.4 0.0.0.3 area 0
!
router bgp 200
 bgp log-neighbor-changes
 neighbor 4.4.4.4 remote-as 200
 neighbor 4.4.4.4 update-source Loopback0
 neighbor 4.4.4.4 next-hop-self
 neighbor 192.168.1.1 remote-as 100
 

R3:

interface Loopback0
 ip address 3.3.3.3 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.9 255.255.255.252
!
interface FastEthernet0/1
 ip address 192.168.1.6 255.255.255.252
!
router ospf 1
 router-id 3.3.3.3
 network 3.3.3.3 0.0.0.0 area 0
 network 192.168.1.4 0.0.0.3 area 0
 network 192.168.1.8 0.0.0.3 area 0
 

R4:

interface Loopback0
 ip address 4.4.4.4 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.1.13 255.255.255.252
!
interface FastEthernet0/1
 ip address 192.168.1.10 255.255.255.252
!
router ospf 1
 router-id 4.4.4.4
 redistribute bgp 200 subnets
 network 4.4.4.4 0.0.0.0 area 0
 network 192.168.1.8 0.0.0.3 area 0
!
router bgp 200
 bgp log-neighbor-changes
 neighbor 2.2.2.2 remote-as 200
 neighbor 2.2.2.2 update-source Loopback0
 neighbor 2.2.2.2 next-hop-self
 neighbor 192.168.1.14 remote-as 300

說明: 由於水平分割的抑制,BGP路由器從IBGP鄰居收的路由不會再傳遞給IBGP鄰居,這是爲了防止環路的產生。即便R2與R三、R3與R4創建了鄰居關係,在沒有其餘設置的狀況下,R3也不會將R2傳遞來的路由傳遞給R4,一樣R3也不會將R4傳遞過來的路由給R2。

相關文章
相關標籤/搜索