目录
BGP联邦综合实验
实验图
网段划分
基础配置
路由配置
启动AS2中的ospf--- IGP协议
检测IGP
启动AS之间的BGP
测试
发布R1路由
修改：下一跳解决上述问题
解决水平分割
发布R8路由
测试
AS2内部环回路由信息互相访问
配置空接口
发布静态路由
测试
存在问题：
解决办法：
解决：环回地址192.168.2.0 /24不能在任何协议中宣告
BGP联邦综合实验
实验图
网段划分
已知整个AS2的IP地址为172.16..0.0/16
172.16.0.0/16 ---- 172.16.2.0/24 ---- R2
172.16.3.0/24 ---- R3
172.16.4.0/24 ---- R4
172.16.5.0/24 ---- R5
172.16.6.0/24 ---- R6
172.16.7.0/24 ---- R7
172.16.0.0/24 ---- P2P
172.16.1.0/24 ---- MA -----172.16.1.0/29 ----- R2-R3
172.16.1.8/29 ----- R2-R4
172.16.1.16/29 ----- R3-R4
172.16.1.24/29 ----- R4-R7
172.16.1.32/29 ----- R5-R6
172.16.1.40/29 ----- R6-R7
172.16.1.48/29
......
基础配置
R1
[R1]display ip interface brief
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 4
The number of interface that is DOWN in Physical is 2
The number of interface that is UP in Protocol is 4
The number of interface that is DOWN in Protocol is 2
Interface IP Address/Mask Physical Protocol
GigabitEthernet0/0/0 12.0.0.1/24 up up
GigabitEthernet0/0/1 unassigned down down
GigabitEthernet0/0/2 unassigned down down
LoopBack0 192.168.1.1/24 up up(s)
LoopBack1 10.0.0.1/24 up up(s)
NULL0 unassigned up up(s)
R2
[R2]display ip interface brief
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 5
The number of interface that is DOWN in Physical is 0
The number of interface that is UP in Protocol is 5
The number of interface that is DOWN in Protocol is 0
Interface IP Address/Mask Physical Protocol
GigabitEthernet0/0/0 12.0.0.2/24 up up
GigabitEthernet0/0/1 172.16.1.1/29 up up
GigabitEthernet0/0/2 172.16.1.9/29 up up
LoopBack0 172.16.2.1/24 up up(s)
NULL0 unassigned up up(s)
R3
[R3]display ip interface brief
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 4
The number of interface that is DOWN in Physical is 1
The number of interface that is UP in Protocol is 4
The number of interface that is DOWN in Protocol is 1
Interface IP Address/Mask Physical Protocol
GigabitEthernet0/0/0 172.16.1.2/29 up up
GigabitEthernet0/0/1 172.16.1.17/29 up up
GigabitEthernet0/0/2 unassigned down down
LoopBack0 172.16.3.1/24 up up(s)
NULL0 unassigned up up(s)
R4
[R4]display ip interface brief
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 4
The number of interface that is DOWN in Physical is 1
The number of interface that is UP in Protocol is 4
The number of interface that is DOWN in Protocol is 1
Interface IP Address/Mask Physical Protocol
GigabitEthernet0/0/0 172.16.1.18/29 up up
GigabitEthernet0/0/1 172.16.1.25/29 up up
GigabitEthernet0/0/2 unassigned down down
LoopBack0 172.16.4.1/24 up up(s)
NULL0 unassigned up up(s)
[R4]R5
[R5]display ip interface brief
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 4
The number of interface that is DOWN in Physical is 1
The number of interface that is UP in Protocol is 4
The number of interface that is DOWN in Protocol is 1
Interface IP Address/Mask Physical Protocol
GigabitEthernet0/0/0 172.16.1.10/29 up up
GigabitEthernet0/0/1 172.16.1.33/29 up up
GigabitEthernet0/0/2 unassigned down down
LoopBack0 172.16.5.1/24 up up(s)
NULL0 unassigned up up(s)
R6
[R6]display ip interface brief
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 4
The number of interface that is DOWN in Physical is 1
The number of interface that is UP in Protocol is 4
The number of interface that is DOWN in Protocol is 1
Interface IP Address/Mask Physical Protocol
GigabitEthernet0/0/0 172.16.1.34/29 up up
GigabitEthernet0/0/1 172.16.1.41/29 up up
GigabitEthernet0/0/2 unassigned down down
LoopBack0 172.16.6.1/24 up up(s)
NULL0 unassigned up up(s)
R7
[R7]display ip interface brief
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 5
The number of interface that is DOWN in Physical is 0
The number of interface that is UP in Protocol is 5
The number of interface that is DOWN in Protocol is 0
Interface IP Address/Mask Physical Protocol
GigabitEthernet0/0/0 172.16.1.42/29 up up
GigabitEthernet0/0/1 172.16.1.26/29 up up
GigabitEthernet0/0/2 78.0.0.1/24 up up
LoopBack0 172.16.7.1/24 up up(s)
NULL0 unassigned up up(s)
R8
[R8]display ip interface brief
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 4
The number of interface that is DOWN in Physical is 2
The number of interface that is UP in Protocol is 4
The number of interface that is DOWN in Protocol is 2
Interface IP Address/Mask Physical Protocol
GigabitEthernet0/0/0 78.0.0.2/24 up up
GigabitEthernet0/0/1 unassigned down down
GigabitEthernet0/0/2 unassigned down down
LoopBack0 192.168.2.1/24 up up(s)
LoopBack1 11.0.0.1/24 up up(s)
NULL0 unassigned up up(s) 路由配置
启动AS2中的ospf--- IGP协议
R2
[R2]ospf 1 router-id 2.2.2.2
[R2-ospf-1]a 0
[R2-ospf-1]a 0
[R2-ospf-1-area-0.0.0.0]netwo
[R2-ospf-1-area-0.0.0.0]network 172.16.0.0 0.0.0.255
[R2-ospf-1-area-0.0.0.0]R3
[R3]ospf 1 router-id 3.3.3.3
[R3-ospf-1]area 0
[R3-ospf-1-area-0.0.0.0]network 172.16.0.0 0.0.255.255
注意：
其他R4R5,R6,R7,R8类似
检测IGP
R2
[R2]display ip routing-table protocol ospf
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Public routing table : OSPF
Destinations : 9 Routes : 10
OSPF routing table status : <Active>
Destinations : 9 Routes : 10
Destination/Mask Proto Pre Cost Flags NextHop Interface
172.16.1.16/29 OSPF 10 2 D 172.16.1.2 GigabitEthernet
0/0/1
172.16.1.24/29 OSPF 10 3 D 172.16.1.2 GigabitEthernet
0/0/1
172.16.1.32/29 OSPF 10 2 D 172.16.1.10 GigabitEthernet
0/0/2
172.16.1.40/29 OSPF 10 3 D 172.16.1.10 GigabitEthernet
0/0/2
172.16.3.1/32 OSPF 10 1 D 172.16.1.2 GigabitEthernet
0/0/1
172.16.4.1/32 OSPF 10 2 D 172.16.1.2 GigabitEthernet
0/0/1
172.16.5.1/32 OSPF 10 1 D 172.16.1.10 GigabitEthernet
0/0/2
172.16.6.1/32 OSPF 10 2 D 172.16.1.10 GigabitEthernet
0/0/2
172.16.7.1/32 OSPF 10 3 D 172.16.1.10 GigabitEthernet
0/0/2
OSPF 10 3 D 172.16.1.2 GigabitEthernet
0/0/1
OSPF routing table status : <Inactive>
Destinations : 0 Routes : 0
R3
[R3]display ip routing-table protocol ospf
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Public routing table : OSPF
Destinations : 9 Routes : 10
OSPF routing table status : <Active>
Destinations : 9 Routes : 10
Destination/Mask Proto Pre Cost Flags NextHop Interface
172.16.1.8/29 OSPF 10 2 D 172.16.1.1 GigabitEthernet
0/0/0
172.16.1.24/29 OSPF 10 2 D 172.16.1.18 GigabitEthernet
0/0/1
172.16.1.32/29 OSPF 10 3 D 172.16.1.1 GigabitEthernet
0/0/0
172.16.1.40/29 OSPF 10 3 D 172.16.1.18 GigabitEthernet
0/0/1
172.16.2.1/32 OSPF 10 1 D 172.16.1.1 GigabitEthernet
0/0/0
172.16.4.1/32 OSPF 10 1 D 172.16.1.18 GigabitEthernet
0/0/1
172.16.5.1/32 OSPF 10 2 D 172.16.1.1 GigabitEthernet
0/0/0
172.16.6.1/32 OSPF 10 3 D 172.16.1.1 GigabitEthernet
0/0/0
OSPF 10 3 D 172.16.1.18 GigabitEthernet
0/0/1
172.16.7.1/32 OSPF 10 2 D 172.16.1.18 GigabitEthernet
0/0/1
OSPF routing table status : <Inactive>
Destinations : 0 Routes : 0
启动AS之间的BGP
R1
[R1]bgp 1
[R1-bgp]ro
[R1-bgp]router-id 1.1.1.1
[R1-bgp]pe
[R1-bgp]peer 12.0.0.2 as
[R1-bgp]peer 12.0.0.2 as-number 2
[R1-bgp]R2
[R2]bgp 64512 ---- 有联邦存在的时候写联邦AS号
[R2-bgp]router-id 2.2.2.2
[R2-bgp]confederation id 2 --- 告诉大AS号为2
[R2-bgp]confederation peer-as 64513 --- 指定EBGP对等体关系的AS号
[R2-bgp]peer 12.0.0.1 as-number 1
[R2-bgp]peer 172.16.3.1 as-number 64512 --- 建立 R2 与 R3 的IGP对等体关系
[R2-bgp]peer 172.16.3.1 connect-interface LoopBack 0
[R2-bgp]peer 172.16.5.1 as-number 64513 --- 建立 R2 与 R5 的非直连建邻
[R2-bgp]peer 172.16.5.1 connect-interface LoopBack 0
[R2-bgp]peer 172.16.5.1 ebgp-max-hop --- 将ttl值修改 R3
[R3]bgp 64512
[R3-bgp]router-id 3.3.3.3
[R3-bgp]confederation id 2
[R3-bgp]peer 172.16.2.1 as-number 64512
[R3-bgp]peer 172.16.2.1 connect-interface LoopBack 0
[R3-bgp]peer 172.16.4.1 as-number 64512
[R3-bgp]peer 172.16.4.1 connect-interface LoopBack 0
R4
[R4]bgp 64512
[R4-bgp]router-id 4.4.4.4
[R4-bgp]confederation id 2
[R4-bgp]confederation peer-as 64513
[R4-bgp]peer 172.16.3.1 as 64512
[R4-bgp]peer 172.16.3.1 connect-interface LoopBack 0
[R4-bgp]peer 172.16.7.1 as 64513
[R4-bgp]peer 172.16.7.1 connect-interface LoopBack 0
[R4-bgp]peer 172.16.7.1 ebgp-max-hop
注意：
R5与R4类似，R6与R3类似，R7与R2类似
R8
[R8]bgp 3
[R8-bgp]router-id 8.8.8.8
[R8-bgp]peer 78.0.0.1 as 2
[R8-bgp]测试
R2
[R2]display bgp peer
BGP local router ID : 2.2.2.2
Local AS number : 64512
Total number of peers : 3 Peers in established state : 3
Peer V AS MsgRcvd MsgSent OutQ Up/Down State Pre
fRcv
12.0.0.1 4 1 19 19 0 00:17:28 Established
0
172.16.3.1 4 64512 14 16 0 00:12:21 Established
0
172.16.5.1 4 64513 8 10 0 00:06:11 Established
0
R3
[R3]display bgp peer
BGP local router ID : 3.3.3.3
Local AS number : 64512
Total number of peers : 2 Peers in established state : 2
Peer V AS MsgRcvd MsgSent OutQ Up/Down State Pre
fRcv
172.16.2.1 4 64512 14 14 0 00:12:49 Established
0
172.16.4.1 4 64512 11 14 0 00:09:49 Established
0
[R3]
R4
[R4]display bgp peer
BGP local router ID : 4.4.4.4
Local AS number : 64512
Total number of peers : 2 Peers in established state : 2
Peer V AS MsgRcvd MsgSent OutQ Up/Down State Pre
fRcv
172.16.3.1 4 64512 12 12 0 00:10:18 Established
0
172.16.7.1 4 64513 5 7 0 00:03:14 Established
0
[R4]
R5
[R5]display bgp peer
BGP local router ID : 5.5.5.5
Local AS number : 64513
Total number of peers : 2 Peers in established state : 2
Peer V AS MsgRcvd MsgSent OutQ Up/Down State Pre
fRcv
172.16.2.1 4 64512 9 9 0 00:07:24 Established
0
172.16.6.1 4 64513 8 9 0 00:06:14 Established
0
[R5]
R6
[R6]display bgp peer
BGP local router ID : 6.6.6.6
Local AS number : 64513
Total number of peers : 2 Peers in established state : 2
Peer V AS MsgRcvd MsgSent OutQ Up/Down State Pre
fRcv
172.16.5.1 4 64513 8 8 0 00:06:25 Established
0
172.16.7.1 4 64513 6 7 0 00:04:36 Established
0
[R6]
R7
[R7]display bgp peer
BGP local router ID : 7.7.7.7
Local AS number : 64513
Total number of peers : 3 Peers in established state : 3
Peer V AS MsgRcvd MsgSent OutQ Up/Down State Pre
fRcv
78.0.0.2 4 3 5 6 0 00:03:29 Established
0
172.16.4.1 4 64512 6 6 0 00:04:07 Established
0
172.16.6.1 4 64513 7 7 0 00:05:01 Established
0
R8
[R8]display bgp peer
BGP local router ID : 8.8.8.8
Local AS number : 3
Total number of peers : 1 Peers in established state : 1
Peer V AS MsgRcvd MsgSent OutQ Up/Down State Pre
fRcv
78.0.0.1 4 2 5 5 0 00:03:48 Established
0
[R8]
发布R1路由
R1
[R1-bgp]network 10.0.0.0 24
[R1-bgp]display bgp peer 测试
[R1-bgp]display bgp routing-table
BGP Local router ID is 1.1.1.1
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
*> 10.0.0.0/24 0.0.0.0 0 0 i
<R2>display bgp routing-table
BGP Local router ID is 2.2.2.2
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
*> 10.0.0.0/24 12.0.0.1 0 0 1i
<R2>
<R3>display bgp routing-table ---- 收到但不可用
BGP Local router ID is 3.3.3.3
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 10.0.0.0/24 12.0.0.1 0 100 0 1i
<R3>
R3与R5可以收到但不可用，所以R4，R6不能收到，包括后面
修改：下一跳解决上述问题
R2
[R2]bgp 64512
[R2-bgp]peer 172.16.3.1 next-hop-local
[R2-bgp]peer 172.16.5.1 next-hop-local
测试
R3
<R3>display bgp routing-table
BGP Local router ID is 3.3.3.3
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 10.0.0.0/24 172.16.2.1 0 100 0 1i
<R3>
R6
<R6>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 10.0.0.0/24 172.16.2.1 0 100 0 (64512) 1i
<R6>注意:
R4收不到，原因：IBGP的水平分割导致
R6收到，原因：R5与R2为联邦BGP 属于EBGP对等体，EBGP学到的路由信息可以发给自己的IBGP对等体
R7收不到，原因：IBGP的水平分割
解决水平分割
设置路由反射器
R3作为反射指定R2作为客户
[R3]bgp
[R3]bgp 64512
[R3-bgp]peer 172.16.2.1 reflect-client --- 指定R2作为客户测试
<R4>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 10.0.0.0/24 172.16.2.1 0 100 0 1i
<R4>
<R4>display bgp routing-table 10.0.0.0
BGP local router ID : 4.4.4.4
Local AS number : 64512
Paths: 1 available, 1 best, 1 select
BGP routing table entry information of 10.0.0.0/24:
From: 172.16.3.1 (3.3.3.3)
Route Duration: 00h01m23s
Relay IP Nexthop: 172.16.1.17
Relay IP Out-Interface: GigabitEthernet0/0/0
Original nexthop: 172.16.2.1
Qos information : 0x0
AS-path 1, origin igp, MED 0, localpref 100, pref-val 0, valid, internal-confed
, best, select, active, pre 255, IGP cost 2
Originator: 2.2.2.2
Cluster list: 3.3.3.3
Advertised to such 1 peers:
172.16.7.1
<R4>同理R6作为反射指定R7或R5作为客户
[R6]bgp 64513
[R6-bgp]peer 172.16.7.1 reflect-client 测试
[R7]display bgp routing-table
BGP Local router ID is 7.7.7.7
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total Number of Routes: 2
Network NextHop MED LocPrf PrefVal Path/Ogn
*>i 10.0.0.0/24 172.16.2.1 0 100 0 (64512) 1i
* i 172.16.2.1 0 100 0 (64512) 1i
[R7]收到两条一样的，R6反射一条，R4收到反射R7
<R8>display bgp routing-table
BGP Local router ID is 8.8.8.8
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
*> 10.0.0.0/24 78.0.0.1 0 2 1i
<R8>目前R1发送路由已经完全做通
发布R8路由
[R8]bgp 3
[R8-bgp]network 11.0.0.0 24测试
[R7]display bgp routing-table
BGP Local router ID is 7.7.7.7
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total Number of Routes: 3
Network NextHop MED LocPrf PrefVal Path/Ogn
*>i 10.0.0.0/24 172.16.2.1 0 100 0 (64512) 1i
* i 172.16.2.1 0 100 0 (64512) 1i
*> 11.0.0.0/24 78.0.0.2 0 0 3i
[R7]因为下一跳的地址为78.0.0.2 所以R4与R6收不到路由信息，解决办法：修改为本地路由信息
[R7]bgp 64513 [R7-bgp]peer 172.16.6.1 next-hop-local [R7-bgp]peer 172.16.4.1 next-hop-local [R7-bgp]
<R1>display bgp routing-table
BGP Local router ID is 1.1.1.1
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total Number of Routes: 2
Network NextHop MED LocPrf PrefVal Path/Ogn
*> 10.0.0.0/24 0.0.0.0 0 0 i
*> 11.0.0.0/24 12.0.0.2 0 2 3i
<R1>因为发送路由信息以及互通，所以R1与R8路由已经可以互相访问
AS2内部环回路由信息互相访问
路由聚合
进行路由汇总：
172.16.2.0/24
172.16.3.0/24
172.16.4.0/24
172.16.5.0/24
172.16.6.0/24
172.16.7.0/24 ----- 172.16.0.0 / 21
配置空接口
[R2]ip route-static 172.16.0.0 21 NULL 0
[R2]display ip routing-table protocol static
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Public routing table : Static
Destinations : 1 Routes : 1 Configured Routes : 1
Static routing table status : <Active>
Destinations : 1 Routes : 1
Destination/Mask Proto Pre Cost Flags NextHop Interface
172.16.0.0/21 Static 60 0 D 0.0.0.0 NULL0
Static routing table status : <Inactive>
Destinations : 0 Routes : 0
[R2]发布静态路由
[R2]bgp 64512
[R2-bgp]network 172.16.0.0 21
[R2-bgp]display bgp routing-table
BGP Local router ID is 2.2.2.2
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total Number of Routes: 3
Network NextHop MED LocPrf PrefVal Path/Ogn
*> 10.0.0.0/24 12.0.0.1 0 0 1i
*>i 11.0.0.0/24 172.16.7.1 0 100 0 (64513) 3i
*> 172.16.0.0/21 0.0.0.0 0 0 i
[R2-bgp]测试
[R1]display bgp routing-table
BGP Local router ID is 1.1.1.1
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total Number of Routes: 3
Network NextHop MED LocPrf PrefVal Path/Ogn
*> 10.0.0.0/24 0.0.0.0 0 0 i
*> 11.0.0.0/24 12.0.0.2 0 2 3i
*> 172.16.0.0/21 12.0.0.2 0 0 2i
[R1]
<R7>display bgp routing-table
BGP Local router ID is 7.7.7.7
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total Number of Routes: 5
Network NextHop MED LocPrf PrefVal Path/Ogn
*>i 10.0.0.0/24 172.16.2.1 0 100 0 (64512) 1i
* i 172.16.2.1 0 100 0 (64512) 1i
*> 11.0.0.0/24 78.0.0.2 0 0 3i
*>i 172.16.0.0/21 172.16.2.1 0 100 0 (64512)i
* i 172.16.2.1 0 100 0 (64512)i
<R7>
<R8>display bgp routing-table
BGP Local router ID is 8.8.8.8
Status codes: * - valid, > - best, d - damped,
h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Total Number of Routes: 3
Network NextHop MED LocPrf PrefVal Path/Ogn
*> 10.0.0.0/24 78.0.0.1 0 2 1i
*> 11.0.0.0/24 0.0.0.0 0 0 i
*> 172.16.0.0/21 78.0.0.1 0 2i
<R8>目前已完成整个网络所有设备的环回都可以互相访问
存在问题：
如果R8发送172.16.0.1（路由黑洞）发送给R7，最终被R2丢掉会使得黑洞在AS2内部占用从而浪费资源
解决办法：
[R7]ip route-static 172.16.0.0 21 NULL 0
[R7]bgp 64513
[R7-bgp]network 172.16.0.0 21
[R7-bgp]解决：环回地址192.168.2.0 /24不能在任何协议中宣告
制作GRE隧道
[R1]int t 0/0/0
[R1-Tunnel0/0/0]ip ad
[R1-Tunnel0/0/0]ip address 99.0.0.1 24 ---- 配置网段
[R1-Tunnel0/0/0]
[R1-Tunnel0/0/0]tunnel-protocol gre --- 定义隧道的封装类型
[R1-Tunnel0/0/0]source 10.0.0.1 ---定义封装内容
[R1-Tunnel0/0/0]destination 11.0.0.1
Mar 2 2023 12:18:54-08:00 R1 %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IP
on the interface Tunnel0/0/0 has entered the UP state.
[R1-Tunnel0/0/0]
[R1-Tunnel0/0/0][R8]int t 0/0/0
[R8-Tunnel0/0/0]ip address 99.0.0.2 24
[R8-Tunnel0/0/0]tunnel-protocol gre
[R8-Tunnel0/0/0]source 11.0.0.1
[R8-Tunnel0/0/0]destination 10.0.0.1
Mar 2 2023 12:18:00-08:00 R8 %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IP
on the interface Tunnel0/0/0 has entered the UP state.
[R8-Tunnel0/0/0]
[R8-Tunnel0/0/0]配置静态路由
[R1]ip route-static 192.168.2.0 24 99.0.0.2[R8]ip route-static 192.168.1.0 24 99.0.0.1 测试
[R8]ping -a 192.168.2.1 192.168.1.1
PING 192.168.1.1: 56 data bytes, press CTRL_C to break
Reply from 192.168.1.1: bytes=56 Sequence=1 ttl=255 time=60 ms
Reply from 192.168.1.1: bytes=56 Sequence=2 ttl=255 time=50 ms
Reply from 192.168.1.1: bytes=56 Sequence=3 ttl=255 time=30 ms
Reply from 192.168.1.1: bytes=56 Sequence=4 ttl=255 time=50 ms
Reply from 192.168.1.1: bytes=56 Sequence=5 ttl=255 time=30 ms
--- 192.168.1.1 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 30/44/60 ms
[R8]
