R1#sh run
Building configuration...
……….
interface Ethernet0/0
ip address 192.168.1.1 255.255.255.0
half-duplex
glbp 1 ip 192.168.1.254
glbp 1 priority 200
glbp 1 preempt
!
interface Ethernet0/1
ip address 192.168.2.1 255.255.255.0
half-duplex
router rip
version 2
passive-interface Ethernet0/0
network 192.168.1.0
network 192.168.2.0
no auto-summary
!
R2#sh run
Building configuration...
………….
interface Ethernet0/0
ip address 192.168.1.2 255.255.255.0
half-duplex
glbp 1 ip 192.168.1.254
glbp 1 priority 180
glbp 1 preempt
!
interface Ethernet0/1
ip address 192.168.2.2 255.255.255.0
half-duplex
!
router rip
version 2
passive-interface Ethernet0/0
network 192.168.1.0
network 192.168.2.0
!
R3#sh run
Building configuration...
………..
interface Ethernet0/0
ip address 192.168.1.3 255.255.255.0
half-duplex
glbp 1 ip 192.168.1.254
glbp 1 priority 160
glbp 1 preempt
!
interface Ethernet0/1
ip address 192.168.2.3 255.255.255.0
half-duplex
!
router rip
version 2
passive-interface Ethernet0/0
network 192.168.1.0
network 192.168.2.0
!
其他设配的配置按照拓扑图配置，确保直连链路的连通性。
（1）在R1上查看GLBP的信息：
R1#sh glbp
Ethernet0/0 - Group 1
State is Active
2 state changes, last state change 00:18:28
Virtual IP address is 192.168.1.254 // 虚拟网关是192.168.1.254
Hello time 3 sec, hold time 10 sec
Next hello sent in 1.324 secs
Redirect time 600 sec, forwarder time-out 14400 sec
Preemption enabled, min delay 0 sec
Active is local // 说明R1是活动的AVG
Standby is 192.168.1.2, priority 180 (expires in 9.320 sec) //说明R2是备份AVG
Priority 200 (configured)
Weighting 100 (default 100), thresholds: lower 1, upper 100
Load balancing: round-robin
Group members:
cc01.0d80.0000 (192.168.1.1) local
cc02.0d80.0000 (192.168.1.2)
cc03.0d80.0000 (192.168.1.3) // 显示BGLP的成员
There are 3 forwarders (1 active)
Forwarder 1
State is Active
1 state change, last state change 00:18:18
MAC address is 0007.b400.0101 (default) // 虚拟网关的其中一个MAC地址
此段说明R1是0007.b400.0101的活动路由器，也就是说有发往007.b400.0101的数据，将由R1接收并转发。
Owner ID is cc01.0d80.0000
Redirection enabled
Preemption enabled, min delay 30 sec
Active is local, weighting 100
Forwarder 2
State is Listen
MAC address is 0007.b400.0102 (learnt)
Owner ID is cc02.0d80.0000
Redirection enabled, 598.132 sec remaining (maximum 600 sec)
Time to live: 14398.132 sec (maximum 14400 sec)
Preemption enabled, min delay 30 sec
Active is 192.168.1.2 (primary), weighting 100 (expires in 8.128 sec)
Forwarder 3
State is Listen
MAC address is 0007.b400.0103 (learnt)
Owner ID is cc03.0d80.0000
Redirection enabled, 599.320 sec remaining (maximum 600 sec)
Time to live: 14399.320 sec (maximum 14400 sec)
Preemption enabled, min delay 30 sec
Active is 192.168.1.3 (primary), weighting 100 (expires in 9.316 sec)
从上面得知：
R1: 0007.b400.0101 的活动路由器
R2: 0007.b400.0102 的活动路由器
R3: 0007.b400.0103的活动路由器
（2） 检查GLBP的负载均衡功能
在PC上ping 4.4.4 .4
PC#ping 4.4.4 .4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 4.4.4 .4, timeout is 2 seconds:
.!!!!
再查看ARP表
PC#sh arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 192.168.1.100 - cc05.0d18.0000 ARPA Ethernet0/0
Internet 192.168.1.254 13 0007.b400.0101 ARPA Ethernet0/0
以上表明PC的ARP请求获得网关(192.168.1.254)的MAC为00-07-b4-00-01-01
清空ARP缓存表，再次ping 4.4.4 .4,查看ARP缓存
PC#clear arp
PC#ping 4.4.4 .4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 4.4.4 .4, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/228/1032 ms
PC#sh arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 192.168.1.100 - cc05.0d18.0000 ARPA Ethernet0/0
Internet 192.168.1.254 0 0007.b400.0103 ARPA Ethernet0/0
以上表明PC的ARP请求获得网关(192.168.1.254)的MAC为00-07-b4-00-01-03
也就是说GLBP响应ARP请求时，每次会用不同的MAC响应，从而实现负载平衡。
（3） 检查GLBP的冗余功能
确定了192.168.1.254的MAC地址是0007.b400.0103 ，
在PC上ping 4.4.4 .4 重复1000次，并在中间断开R3的e0/0端口
PC#ping 4.4.4 .4 repeat 1000
Type escape sequence to abort.
Sending 1000, 100-byte ICMP Echos to 4.4.4 .4, timeout is 2 seconds:
.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!.....!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
可以看到在R3发生故障的时候，很快就有其他路由器顶替它的工作。
PC#sh arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 192.168.1.100 - cc05.0d18.0000 ARPA Ethernet0/0
Internet 192.168.1.254 5 0007.b400.0103 ARPA Ethernet0/0
再在R1上查看glbp的信息：
Ethernet0/0 - Group 1
…………
Forwarder 3
State is Listen
4 state changes, last state change 00:01:43
MAC address is 0007.b400.0103 (learnt)
Owner ID is cc03.0d80.0000
Redirection enabled, 597.940 sec remaining (maximum 598 sec)
Time to live: 14397.940 sec (maximum 14398 sec)
Preemption enabled, min delay 30 sec
Active is 192.168.1.2 (secondary), weighting 100 (expires in 9.936 sec)
Arp replies sent: 2
可以看出路由器R2顶替了路由R3的功能，可以看出gblp既有负载均衡的功能还有冗余备份的功能！
