第一步:规划全网 IP 地址
一、梳理需求
1.环回口规划
- AR1(AS1)LoopBack0:10.0.0.0/24 (需宣告)
- AR1 LoopBack1:192.168.1.0/24 (禁止任何协议宣告)
- AR8(AS3)LoopBack0:11.0.0.0/24 (需宣告)
- AR8 LoopBack1:192.168.2.0/24 (禁止任何协议宣告) 要求:两个 192.168 私网段不通告,但自身能互通。
2.AS2 整体网段:172.16.0.0/16,拆分给 AS2 内两台子 AS(64512、64513)
- AS64512(AR2、AR3、AR4):分配 172.16.0.0/20
- AS64513(AR5、AR6、AR7):分配 172.16.16.0/20 骨干互联链路全部从这两段里取 / 30 子网(点到点链路标准掩码)
3.AS 间互联链路(AR1-AR2、AR7-AR8)自定义网段
- AR1 GE0/0/0 ↔ AR2 GE0/0/0:100.0.1.0/30
- AR7 GE0/0/2 ↔ AR8 GE0/0/0:100.0.2.0/30
二、分配互联链路 IP
1)AS 间链路
AR1 GE0/0/0:100.0.1.1/30
AR2 GE0/0/0:100.0.1.2/30
AR7 GE0/0/2:100.0.2.1/30
AR8 GE0/0/0:100.0.2.2/30
2)AS64512(172.16.0.0/20)内部链路
- AR2 GE0/0/1 ↔ AR3 GE0/0/0:172.16.0.0/30 AR2:172.16.0.1 AR3:172.16.0.2
- AR3 GE0/0/1 ↔ AR4 GE0/0/0:172.16.0.4/30 AR3:172.16.0.5 AR4:172.16.0.6
- AR2 GE0/0/2 ↔ AR5 GE0/0/0:172.16.0.8/30 AR2:172.16.0.9 AR5:172.16.0.10
- AR4 GE0/0/1 ↔ AR7 GE0/0/1:172.16.0.12/30 AR4:172.16.0.13 AR7:172.16.0.14
3)AS64513(172.16.16.0/20)内部链路
- AR5 GE0/0/1 ↔ AR6 GE0/0/0:172.16.16.0/30 AR5:172.16.16.1 AR6:172.16.16.2
- AR6 GE0/0/1 ↔ AR7 GE0/0/0:172.16.16.4/30 AR6:172.16.16.5 AR7:172.16.16.6
三、环回口统一分配(用于 BGP 建立 IBGP 邻居)
AS2 内所有路由器环回 0(IBGP 更新源):
- AR2 LoopBack0:172.16.0.100/32
- AR3 LoopBack0:172.16.0.101/32
- AR4 LoopBack0:172.16.0.102/32
- AR5 LoopBack0:172.16.16.100/32
- AR6 LoopBack0:172.16.16.101/32
- AR7 LoopBack0:172.16.16.102/32
第二步:所有设备基础接口、环回口完整配置
前置
- 环回 0 为 32 位掩码,用于 IBGP 邻居建立;业务环回为 / 24
- 192.168.1.0/24、192.168.2.0/24 仅本地配置,不宣告进任何 IGP/BGP
- 每台配完后用
display ip interface brief核对接口 UP、地址正确
1. AR1(AS1)
sysname AR1 # 业务环回 interface LoopBack0 ip address 10.0.0.1 24 interface LoopBack1 ip address 192.168.1.1 24 # 外联接口 interface GigabitEthernet 0/0/0 ip address 100.0.1.1 302. AR2(AS64512)
sysname AR2 # IBGP环回 interface LoopBack0 ip address 172.16.0.100 32 # 接口 interface GigabitEthernet 0/0/0 ip address 100.0.1.2 30 interface GigabitEthernet 0/0/1 ip address 172.16.0.1 30 interface GigabitEthernet 0/0/2 ip address 172.16.0.9 303. AR3(AS64512)
sysname AR3 interface LoopBack0 ip address 172.16.0.101 32 interface GigabitEthernet 0/0/0 ip address 172.16.0.2 30 interface GigabitEthernet 0/0/1 ip address 172.16.0.5 304. AR4(AS64512)
sysname AR4 interface LoopBack0 ip address 172.16.0.102 32 interface GigabitEthernet 0/0/0 ip address 172.16.0.6 30 interface GigabitEthernet 0/0/1 ip address 172.16.0.13 305. AR5(AS64513)
sysname AR5 interface LoopBack0 ip address 172.16.16.100 32 interface GigabitEthernet 0/0/0 ip address 172.16.0.10 30 interface GigabitEthernet 0/0/1 ip address 172.16.16.1 306. AR6(AS64513)
sysname AR6 interface LoopBack0 ip address 172.16.16.101 32 interface GigabitEthernet 0/0/0 ip address 172.16.16.2 30 interface GigabitEthernet 0/0/1 ip address 172.16.16.5 307. AR7(AS64513)
sysname AR7 interface LoopBack0 ip address 172.16.16.102 32 interface GigabitEthernet 0/0/0 ip address 172.16.16.6 30 interface GigabitEthernet 0/0/1 ip address 172.16.0.14 30 interface GigabitEthernet 0/0/2 ip address 100.0.2.1 308. AR8(AS3)
sysname AR8 # 业务环回 interface LoopBack0 ip address 11.0.0.1 24 interface LoopBack1 ip address 192.168.2.1 24 # 外联接口 interface GigabitEthernet 0/0/0 ip address 100.0.2.2 30第三步:AS2 内部部署双 OSPF 进程
(AS64512 用 OSPF 1,AS64513 用 OSPF 2)
需求说明:
- AS2 整体网段
172.16.0.0/16,分两个 OSPF 域,仅宣告骨干互联 + 环回 0(IBGP 用的 32 位环回) - 不宣告
192.168.1.0/24、192.168.2.0/24,符合题目要求 - 环回口配置
loopback-stub-net保证 32 位路由传递 - 两台 OSPF 边界设备 AR2、AR7 互相引入对方 OSPF 进程路由,实现 AS2 全网互通
1. AR2
ospf 1 router-id 172.16.0.100 loopback-stub-net area 0 network 172.16.0.0 0.0.31.255 network 172.16.0.100 0.0.0.0 # 引入OSPF2路由,打通上下两个子AS import-route ospf 22. AR3
ospf 1 router-id 172.16.0.101 loopback-stub-net area 0 network 172.16.0.0 0.0.31.255 network 172.16.0.101 0.0.0.03. AR4
ospf 1 router-id 172.16.0.102 loopback-stub-net area 0 network 172.16.0.0 0.0.31.255 network 172.16.0.102 0.0.0.04. AR5
ospf 2 router-id 172.16.16.100 loopback-stub-net area 0 network 172.16.16.0 0.0.31.255 network 172.16.16.100 0.0.0.05. AR6
ospf 2 router-id 172.16.16.101 loopback-stub-net area 0 network 172.16.16.0 0.0.31.255 network 172.16.16.101 0.0.0.06. AR7
ospf 2 router-id 172.16.16.102 loopback-stub-net area 0 network 172.16.16.0 0.0.31.255 network 172.16.16.102 0.0.0.0 # 引入OSPF1路由,打通上下两个子AS import-route ospf 1AR2 ping AR7 环回 0172.16.16.102、AR7 ping AR2 环回 0172.16.0.100,能通代表双 OSPF 互通正常
第四步:BGP 整体配置
(分三部分:EBGP、IBGP、路由宣告、路由聚合防环路)
整体规划说明
- AS 号:
- AS1:AR1 独立 AS
- AS64512:AR2/AR3/AR4
- AS64513:AR5/AR6/AR7
- AS3:AR8 独立 AS
- EBGP 邻居:直连接口 IP 建立
- AR1 ↔ AR2
- AR7 ↔ AR8
- IBGP 邻居:用环回 0 建立,更新源为本机 LoopBack0,全互联 IBGP(保证全网路由可达)
- 路由宣告规则:
- AR1 宣告:
10.0.0.0/24(不宣告 192.168.1.0/24) - AR8 宣告:
11.0.0.0/24(不宣告 192.168.2.0/24) - AS2 边界 AR2、AR7 分别聚合
172.16.0.0/16对外发布,减少路由条目
- AR1 宣告:
- 防环机制:IBGP 水平分割、EBGP AS 号防环、聚合路由抑制明细路由
AR1(AS1)BGP 配置
bgp 1 router-id 10.0.0.1 # EBGP邻居AR2 peer 100.0.1.2 as-number 64512 # 宣告业务环回 network 10.0.0.0 255.255.255.0AR2(AS64512)BGP 配置
bgp 64512 router-id 172.16.0.100 # EBGP邻居AR1 peer 100.0.1.1 as-number 1 # IBGP全互联 peer 172.16.0.101 as-number 64512 peer 172.16.0.102 as-number 64512 peer 172.16.16.100 as-number 64513 peer 172.16.16.101 as-number 64513 peer 172.16.16.102 as-number 64513 # IBGP使用环回建邻居,指定更新源 peer 172.16.0.101 connect-interface LoopBack0 peer 172.16.0.102 connect-interface LoopBack0 peer 172.16.16.100 connect-interface LoopBack0 peer 172.16.16.101 connect-interface LoopBack0 peer 172.16.16.102 connect-interface LoopBack0 # 聚合AS2全部网段,抑制明细,减少路由条目 aggregate 172.16.0.0 255.255.0.0 detail-suppressed # 引入OSPF内部路由,保证IBGP互通 import-route ospf 1AR3(AS64512)BGP 配置
bgp 64512 router-id 172.16.0.101 # IBGP全互联 peer 172.16.0.100 as-number 64512 peer 172.16.0.102 as-number 64512 peer 172.16.16.100 as-number 64513 peer 172.16.16.101 as-number 64513 peer 172.16.16.102 as-number 64513 peer 172.16.0.100 connect-interface LoopBack0 peer 172.16.0.102 connect-interface LoopBack0 peer 172.16.16.100 connect-interface LoopBack0 peer 172.16.16.101 connect-interface LoopBack0 peer 172.16.16.102 connect-interface LoopBack0 import-route ospf 1AR4(AS64512)BGP 配置
bgp 64512 router-id 172.16.0.102 # IBGP全互联 peer 172.16.0.100 as-number 64512 peer 172.16.0.101 as-number 64512 peer 172.16.16.100 as-number 64513 peer 172.16.16.101 as-number 64513 peer 172.16.16.102 as-number 64513 peer 172.16.0.100 connect-interface LoopBack0 peer 172.16.0.101 connect-interface LoopBack0 peer 172.16.16.100 connect-interface LoopBack0 peer 172.16.16.101 connect-interface LoopBack0 peer 172.16.16.102 connect-interface LoopBack0 import-route ospf 1AR5(AS64513)BGP 配置
bgp 64513 router-id 172.16.16.100 # IBGP全互联 peer 172.16.0.100 as-number 64512 peer 172.16.0.101 as-number 64512 peer 172.16.0.102 as-number 64512 peer 172.16.16.101 as-number 64513 peer 172.16.16.102 as-number 64513 peer 172.16.0.100 connect-interface LoopBack0 peer 172.16.0.101 connect-interface LoopBack0 peer 172.16.0.102 connect-interface LoopBack0 peer 172.16.16.101 connect-interface LoopBack0 peer 172.16.16.102 connect-interface LoopBack0 import-route ospf 2AR6(AS64513)BGP 配置
bgp 64513 router-id 172.16.16.101 # IBGP全互联 peer 172.16.0.100 as-number 64512 peer 172.16.0.101 as-number 64512 peer 172.16.0.102 as-number 64512 peer 172.16.16.100 as-number 64513 peer 172.16.16.102 as-number 64513 peer 172.16.0.100 connect-interface LoopBack0 peer 172.16.0.101 connect-interface LoopBack0 peer 172.16.0.102 connect-interface LoopBack0 peer 172.16.16.100 connect-interface LoopBack0 peer 172.16.16.102 connect-interface LoopBack0 import-route ospf 2AR7(AS64513)BGP 配置
bgp 64513 router-id 172.16.16.102 # EBGP邻居AR8 peer 100.0.2.2 as-number 3 # IBGP全互联 peer 172.16.0.100 as-number 64512 peer 172.16.0.101 as-number 64512 peer 172.16.0.102 as-number 64512 peer 172.16.16.100 as-number 64513 peer 172.16.16.101 as-number 64513 peer 172.16.0.100 connect-interface LoopBack0 peer 172.16.0.101 connect-interface LoopBack0 peer 172.16.0.102 connect-interface LoopBack0 peer 172.16.16.100 connect-interface LoopBack0 peer 172.16.16.101 connect-interface LoopBack0 # 聚合AS2全部网段,抑制明细,减少路由条目 aggregate 172.16.0.0 255.255.0.0 detail-suppressed import-route ospf 2AR8(AS3)BGP 配置
bgp 3 router-id 11.0.0.1 # EBGP邻居AR7 peer 100.0.2.1 as-number 64513 # 宣告业务环回 network 11.0.0.0 255.255.255.0跨 AS 连通测试:AR1 ping AR8 环回 011.0.0.1、AR8 ping AR1 环回 010.0.0.1
第五步:全网实验最终验收校验
分层验证标准
1.私有环回网段约束校验
需求:192.168.1.0/24、192.168.2.0/24 仅本机可 ping 通,不发布进 OSPF、BGP 任何路由协议,全网其他设备无法访问。
验证命令:
# AR1自测 ping 192.168.1.1 # AR1访问对端私有环回(必然不通) ping 11.0.0.1 ping 192.168.2.1 # AR8自测 ping 192.168.2.1 # AR8访问对端私有环回(必然不通) ping 10.0.0.1 ping 192.168.1.1合格判定:本机 ping 自身环回 0 丢包;跨设备私有网段全部超时无回复。
2. 业务骨干网段全网互通校验
需求:AR1 业务网段 10.0.0.0/24、AR8 业务网段 11.0.0.0/24、AS2 聚合网段 172.16.0.0/16 全网任意设备互通。
必测命令:
# 跨AS核心连通测试 AR1 ping 11.0.0.1 AR8 ping 10.0.0.1 # 跨子AS环回互通测试 AR1 ping 172.16.16.102 AR8 ping 172.16.0.100 AR3 ping 172.16.16.100合格判定:全部 ping 通,0% 丢包。
BGP 路由条目优化校验
(题目要求减少路由条目)
display bgp routing-table