例如:1.Linux雙網卡綁定實現
2．服務器羣集
網絡設備（路由）方向：
例如:1.VRRP HSRP在企業網中的應用（用在LAN中）
2.浮動靜態路由（WAN）
網絡設備（鏈路）方向：
例如：1.standby interface備份中心 (WAN)
2.鏈路捆綁 (WAN)
3.鏈路聚合 (端口匯聚，用在LAN中)
WAN中高可用性網絡
案例
1.浮動靜態路由(鏈路質量不相等、優先級不等，ospf優先級爲10，靜態路由爲60)
拓撲圖：
路由器R1配置過程：
inter e0
ip add 192.168.1.100 24
inter s0
ip add 192.168.2.1 24
inter s1
ip add 192.168.3.1 24
ospf enable
inter e0
ospf enable area 0
inter s0
ospf enable area 0
ip route 192.168.4.0 24 192.168.3.2
路由器R2配置過程：
inter e0
ip add 192.168.4.100 24
inter s0
ip add 192.168.2.2 24
shut
undo shut(必須進行復位)
inter s1
ip add 192.168.3.2 24
shut
undo shut
ospf enable
inter e0
ospf enable area 0
inter s0
ospf enable area 0
ip route 192.168.1.0 24 192.168.3.1
客戶端上測試：
C:\Documents and Settings\Administrator>tracert 192.168.4.200
Tracing route to 192.168.4.200 over a maximum of 30 hops
1 <1 ms <1 ms <1 ms 192.168.1.100
2 22 ms 22 ms 22 ms 192.168.3.2
3 27 ms 27 ms 27 ms 192.168.4.200
Trace complete.
關閉路由器R1的s0端口後
客戶端上測試：
C:\Documents and Settings\Administrator>tracert 192.168.4.200
Tracing route to 192.168.4.200 over a maximum of 30 hops
1 <1 ms <1 ms <1 ms 192.168.1.100
2 22 ms 22 ms 22 ms 192.168.2.2
3 27 ms 27 ms 27 ms 192.168.4.200
Trace complete.
2.standby interface（鏈路質量相等、節省資金、按照流量計費）
拓撲圖：
路由器R1配置過程：
inter e0
ip add 192.168.1.100 24
inter s0
ip add 192.168.2.1 24
inter s1
ip add 192.168.3.1 24
ip route 192.168.4.0 24 192.168.2.2
ip route 192.168.4.0 24 192.168.3.2
inter s0
standby inter s1
standby timer enable-delay 5
standby timer disable-delay 5
路由器R2配置過程：
inter e0
ip add 192.168.4.100 24
inter s0
ip add 192.168.2.2 24
shut
undo shut //必須進行復位
inter s1
ip add 192.168.3.2 24
shut
undo shut
ip route 192.168.1.0 24 192.168.2.1
ip route 192.168.1.0 24 192.168.3.1
inter s0
standby inter s1
standby timer enable-delay 5
standby timer disable-delay 5 //兩路由器延遲保持一致
測試：
[R1-Serial0]dis ip rout
Routing Tables:
Destination/Mask Proto Pref Metric Nexthop Interface
127.0.0.0/8 Direct 0 0 127.0.0.1 LoopBack0
127.0.0.1/32 Direct 0 0 127.0.0.1 LoopBack0
192.168.2.0/24 Direct 0 0 192.168.2.2 Serial0
192.168.2.1/32 Direct 0 0 127.0.0.1 LoopBack0
192.168.2.2/32 Direct 0 0 192.168.2.2 Serial0
192.168.4.0/24 Static 60 0 192.168.2.2 Serial0
關閉s0端口測試：
[R1-Serial0]dis ip rout
Routing Tables:
Destination/Mask Proto Pref Metric Nexthop Interface
127.0.0.0/8 Direct 0 0 127.0.0.1 LoopBack0
127.0.0.1/32 Direct 0 0 127.0.0.1 LoopBack0
192.168.3.0/24 Direct 0 0 192.168.3.2 Serial1
192.168.3.1/32 Direct 0 0 127.0.0.1 LoopBack0
192.168.3.2/32 Direct 0 0 192.168.3.2 Serial1
192.168.4.0/24 Static 60 0 192.168.3.2 Serial1
3.鏈路捆綁(華爲廣域網封裝默認是ppp，cisco默認是hdlc，把物理口變爲虛擬口)
拓撲圖：
路由器R1配置過程：
inter e0
ip add 192.168.1.100 24
inter s0
ip add 192.168.2.1 24
inter s1
ip add 192.168.3.1 24
inter virtual 1
ip add 192.168.5.1 24
inter s0
ppp mp inter virtual 1
ppp mp //啓用ppp的協商功能
inter s1
ppp mp inter virtual 1
ppp mp
ip route 192.168.4.0 24 192.168.5.2
路由器R2配置過程：
inter e0
ip add 192.168.4.100 24
inter s0
ip add 192.168.2.2 24
shut
undo shut //必須進行復位
inter s1
ip add 192.168.3.2 24
shut
undo shut
inter virtual 1
ip add 192.168.5.2 24
inter s0
ppp mp inter virtual 1
ppp mp //啓用ppp的協商功能
inter s1
ppp mp inter virtual 1
ppp mp
ip route 192.168.1.0 24 192.168.5.1
測試：
Router-Serial0]dis ip rout
Routing Tables:
Destination/Mask Proto Pref Metric Nexthop Interface
127.0.0.0/8 Direct 0 0 127.0.0.1 LoopBack0
127.0.0.1/32 Direct 0 0 127.0.0.1 LoopBack0
192.168.1.0/24 Static 60 0 192.168.5.1 Virtual-Template1
192.168.5.0/24 Direct 0 0 192.168.5.2 Virtual-Template1
192.168.5.1/32 Direct 0 0 192.168.5.2 Virtual-Template1
192.168.5.2/32 Direct 0 0 127.0.0.1 LoopBack0