组网需求
如图所示，有7台设备需要组建IBGP网络，其中AR2、AR4和AR5已经建立了BGP全连接。需求在不破坏AR2、AR4和AR5全连接关系的情况下组建IBGP网络，并尽可能的简化设备的配置和管理。 
配置思路
采用如下的思路配置BGP路由反射器：
- 配置AR2是Cluster1的路由反射器，AR4和AR5是它的两个客户机，配置禁止客户机间通讯，实现不破坏AR2、AR4和AR5全连接关系的情况下组建IBGP网络的需求。
- 配置AR3为Cluster2的路由反射器，AR6和AR7是它的客户机，实现简化设备的配置和管理的需求。公众号同名
操作步骤
配置IP
AR1
<Huawei> <Huawei>sys [Huawei]sys AR1 [AR1]int g0/0/0 [AR1-GigabitEthernet0/0/0]ip add 12.12.12.1 24 [AR1-GigabitEthernet0/0/0]q [AR1]int g0/0/1 [AR1-GigabitEthernet0/0/1]ip add 13.13.13.1 24 [AR1-GigabitEthernet0/0/1]q [AR1]int lo1 [AR1-LoopBack1]ip add 1.1.1.1 24 [AR1-LoopBack1]q
AR2
<Huawei>sys [Huawei]sys AR2 [AR2]int g0/0/0 [AR2-GigabitEthernet0/0/0]ip add 12.12.12.2 24 [AR2-GigabitEthernet0/0/0]q [AR2]int g0/0/1 [AR2-GigabitEthernet0/0/1]ip add 24.24.24.2 24 [AR2-GigabitEthernet0/0/1]q [AR2]int g0/0/2 [AR2-GigabitEthernet0/0/2]ip add 25.25.25.2 24 [AR2-GigabitEthernet0/0/2]q [AR2]int g2/0/0 [AR2-GigabitEthernet2/0/0]ip add 23.23.23.2 24 [AR2-GigabitEthernet2/0/0]q
AR3
<Huawei>sys [Huawei]sys AR3 [AR3]int g0/0/0 [AR3-GigabitEthernet0/0/0]ip add 13.13.13.3 24 [AR3-GigabitEthernet0/0/0]q [AR3]int g0/0/1 [AR3-GigabitEthernet0/0/1]ip add 36.36.36.3 24 [AR3-GigabitEthernet0/0/1]q [AR3]int g0/0/2 [AR3-GigabitEthernet0/0/2]ip add 37.37.37.3 24 [AR3-GigabitEthernet0/0/2]q
AR4
<Huawei>sys [Huawei]sys AR4 [AR4]int g0/0/0 [AR4-GigabitEthernet0/0/0]ip add 24.24.24.4 24 [AR4-GigabitEthernet0/0/0]q [AR4]int g0/0/1 [AR4-GigabitEthernet0/0/1]ip ad 45.45.45.4 24 [AR4-GigabitEthernet0/0/1]q
AR5
<Huawei>sys [Huawei]sys AR5 [AR5]int g0/0/0 [AR5-GigabitEthernet0/0/0]ip add 25.25.25.5 24 [AR5-GigabitEthernet0/0/0]q [AR5]int g0/0/1 [AR5-GigabitEthernet0/0/1]ip ad 45.45.45.5 24 [AR5-GigabitEthernet0/0/1]q
AR6
<Huawei>sys [Huawei]sys AR6 [AR6]int g0/0/0 [AR6-GigabitEthernet0/0/0]ip add 36.36.36.6 24 [AR6-GigabitEthernet0/0/0]q
AR7
<Huawei>sys [Huawei]sys AR7 [AR7]int g0/0/0 [AR7-GigabitEthernet0/0/0]ip add 37.37.37.7 24 [AR7-GigabitEthernet0/0/0]q [AR7]
配置BGP
AR1
[AR1]bgp 100 [AR1-bgp]router-id 1.1.1.1 [AR1-bgp]peer 12.12.12.2 as-number 100 [AR1-bgp]peer 13.13.13.3 as-number 100 [AR1-bgp]ipv4-family unicast [AR1-bgp-af-ipv4]network 1.1.1.0 255.255.255.0 [AR1-bgp-af-ipv4]q
AR2
[AR2]bgp 100 [AR2-bgp]router-id 2.2.2.2 [AR2-bgp]peer 12.12.12.1 as-number 100 [AR2-bgp]peer 23.23.23.3 as-number 100 [AR2-bgp]peer 24.24.24.4 as-number 100 [AR2-bgp]peer 25.25.25.5 as-number 100
AR3
[AR3]bgp 100 [AR3-bgp]router-id 3.3.3.3 [AR3-bgp]peer 13.13.13.1 as-number 100 [AR3-bgp]peer 23.23.23.2 as-number 100 [AR3-bgp]peer 36.36.36.6 as-number 100 [AR3-bgp]peer 37.37.37.7 as-number 100
AR4
[AR4]bgp 100 [AR4-bgp]router-id 4.4.4.4 [AR4-bgp]peer 24.24.24.2 as-number 100 [AR4-bgp]peer 45.45.45.5 as-number 100
AR5
[AR5]bgp 100 [AR5-bgp]router-id 5.5.5.5 [AR5-bgp]peer 25.25.25.2 as-number 100 [AR5-bgp]peer 45.45.45.4 as-number 100
AR6
[AR6]bgp 100 [AR6-bgp]router-id 6.6.6.6 [AR6-bgp]peer 36.36.36.3 as-number 100
AR7
[AR7]bgp 100 [AR7-bgp]router-id 7.7.7.7 [AR7-bgp]peer 37.37.37.3 as-number 100
配置过IBGP的结果
AR1引入了路由1.1.1.0/24，但是AR4、AR5、AR6、AR7、没有关于1.1.1.0/24 BGP路由
配置路由反射器
AR2
#创建对等体组 [AR2-bgp]group 245 internal # 将对等体加入组中 [AR2-bgp]peer 24.24.24.4 group 245 [AR2-bgp]peer 25.25.25.5 group 245 [AR2-bgp]ipv4-family unicast # 将本设备作为 路由反射器 [AR2-bgp-af-ipv4]peer 245 reflect-client # 禁止客户机之间反射路由 [AR2-bgp-af-ipv4]undo reflect between-clients # 配置路由反射器的集群 [AR2-bgp-af-ipv4]reflector cluster-id 1 [AR2-bgp-af-ipv4]q [AR2-bgp]q
AR3
#创建对等体组 [AR3-bgp]group 367 internal # 将对等体加入组中 [AR3-bgp]peer 36.36.36.6 group 367 [AR3-bgp]peer 37.37.37.7 group 367 [AR3-bgp]ipv4-family unicast # 将本设备作为 路由反射器 [AR3-bgp-af-ipv4]peer 367 reflect-client # 禁止客户机之间反射路由 [AR3-bgp-af-ipv4]undo reflect between-clients # 配置路由反射器的集群 [AR3-bgp-af-ipv4]reflector cluster-id 2 [AR3-bgp-af-ipv4]q [AR3-bgp]q
验证
AR4
<AR4>display bgp routing-table 1.1.1.0 BGP local router ID : 4.4.4.4 Local AS number : 100 Paths: 1 available, 0 best, 0 select BGP routing table entry information of 1.1.1.0/24: From: 24.24.24.2 (2.2.2.2) Route Duration: 00h04m20s Relay IP Nexthop: 0.0.0.0 Relay IP Out-Interface: Original nexthop: 12.12.12.1 Qos information : 0x0 AS-path Nil, origin igp, MED 0, localpref 100, pref-val 0, internal, pre 255 Originator: 1.1.1.1 Cluster list: 0.0.0.1 Not advertised to any peer yet <AR4>display bgp routing-table BGP Local router ID is 4.4.4.4 Status codes: * - valid, > - best, d - damped, h - history, i - internal, s - suppressed, S - Stale Origin : i - IGP, e - EGP, ? - incomplete Total Number of Routes: 1 Network NextHop MED LocPrf PrefVal Path/Ogn i 1.1.1.0/24 12.12.12.1 0 100 0 i
AR6
<AR6>display bgp routing-table 1.1.1.0 BGP local router ID : 6.6.6.6 Local AS number : 100 Paths: 1 available, 0 best, 0 select BGP routing table entry information of 1.1.1.0/24: From: 36.36.36.3 (3.3.3.3) Route Duration: 00h00m21s Relay IP Nexthop: 0.0.0.0 Relay IP Out-Interface: Original nexthop: 13.13.13.1 Qos information : 0x0 AS-path Nil, origin igp, MED 0, localpref 100, pref-val 0, internal, pre 255 Originator: 1.1.1.1 Cluster list: 0.0.0.2 Not advertised to any peer yet <AR6>display bgp routing-table BGP Local router ID is 6.6.6.6 Status codes: * - valid, > - best, d - damped, h - history, i - internal, s - suppressed, S - Stale Origin : i - IGP, e - EGP, ? - incomplete Total Number of Routes: 1 Network NextHop MED LocPrf PrefVal Path/Ogn i 1.1.1.0/24 13.13.13.1 0 100 0 i
