网络高可用性的几个案例
实现网络高可用性,简单地说几点就是:出现单点故障时仍然可以通过备份链路实现对网络访问即备份技术或者增加链路带宽、减少链路的负载等等。
典型的有:
路由器上的Vrrp 和hsrp
链路交换机上的Stp、 rstp、 mstp
路由器之间的链路备份:浮动静态路由、接口备份、ppp捆绑
1.浮动静态路由(适用主备链路条件不同)
浮动静态路由是一种特殊的静态路由,通过配置一个比主路由的管理距离更大的静态路由,保证网络中主路由失效的情况下,提供备份路由。但在主路由存在的情况下它不会出现在路由表中。浮动静态路由主要用于拔号备份.
案例拓扑:
实验原理:(huawei 2621路由器)
se0----se0链路作为主链路,启用ospf动态路由(默认管理距离为10)
se1----se1链路作为备用链路,启用静态路由(默认管理距离为60)
进入se0口down掉该端口来模拟主链路故障
参考配置:
[r1]dis cu
Now create configuration...
Current configuration
!
version 1.74
sysname r1
firewall enable
aaa-enable
aaa accounting-scheme optional
!
interface Aux0
async mode flow
link-protocol ppp
!
interface Ethernet0
loopback
ip address 192.168.1.1 255.255.255.0
ospf enable area 0.0.0.0
!
interface Ethernet1
!
interface Serial0
link-protocol ppp
ip address 192.168.3.1 255.255.255.0
ospf enable area 0.0.0.0
shutdown
!
interface Serial1
link-protocol ppp
ip address 192.168.4.1 255.255.255.0
!
ospf enable
!
quit
!
quit
ip route-static 192.168.2.0 255.255.255.0 192.168.4.2 preference 60
!
Return
[r2]dis cu
Now create configuration...
Current configuration
!
version 1.74
sysname r2
undo pos-server addr-switch
firewall enable
aaa-enable
aaa accounting-scheme optional
!
interface Aux0
async mode flow
link-protocol ppp
!
interface Ethernet0
loopback
ip address 192.168.2.1 255.255.255.0
ospf enable area 0.0.0.0
!
interface Ethernet1
!
interface Serial0
clock DTECLK1
link-protocol ppp
ip address 192.168.3.2 255.255.255.0
ospf enable area 0.0.0.0
!
interface Serial1
clock DTECLK1
link-protocol ppp
ip address 192.168.4.2 255.255.255.0
!
ospf enable
!
quit
!
quit
ip route-static 192.168.1.0 255.255.255.0 192.168.4.1 preference 60
!
Return
验证信息:
主链路正常工作时的路由表
[r1]dis ip rou
Routing Tables:
Destination/MaskProtoPrefMetricNexthopInterface
127.0.0.0/8Direct00127.0.0.1 LoopBack0
127.0.0.1/32Direct00127.0.0.1 LoopBack0
192.168.1.0/24Direct00192.168.1.1 Ethernet0
192.168.1.1/32Direct00127.0.0.1 LoopBack0
192.168.2.0/24OSPF101572192.168.3.2 Serial0
192.168.3.0/24Direct00192.168.3.2 Serial0
192.168.3.1/32Direct00127.0.0.1 LoopBack0
192.168.3.2/32Direct00192.168.3.2 Serial0
192.168.4.0/24Direct00192.168.4.2 Serial1
192.168.4.1/32Direct00127.0.0.1 LoopBack0
192.168.4.2/32Direct00192.168.4.2 Serial1
[r2]dis ip rou
Routing Tables:
Destination/MaskProtoPrefMetricNexthopInterface
127.0.0.0/8Direct00127.0.0.1 LoopBack0
127.0.0.1/32Direct00127.0.0.1 LoopBack0
192.168.1.0/24OSPF101572192.168.3.1 Serial0
192.168.2.0/24Direct00192.168.2.1 Ethernet0
192.168.2.1/32Direct00127.0.0.1 LoopBack0
192.168.3.0/24Direct00192.168.3.1 Serial0
192.168.3.1/32Direct00192.168.3.1 Serial0
192.168.3.2/32Direct00127.0.0.1 LoopBack0
192.168.4.0/24Direct00192.168.4.1 Serial1
192.168.4.1/32Direct00192.168.4.1 Serial1
192.168.4.2/32Direct00127.0.0.1 LoopBack0
主链路有故障时的路由表
[r1]dis ip rou
Routing Tables:
Destination/MaskProtoPrefMetricNexthopInterface
127.0.0.0/8Direct00127.0.0.1 LoopBack0
127.0.0.1/32Direct00127.0.0.1 LoopBack0
192.168.1.0/24Direct00192.168.1.1 Ethernet0
192.168.1.1/32Direct00127.0.0.1 LoopBack0
192.168.2.0/24Static600192.168.4.2 Serial1
192.168.4.0/24Direct00192.168.4.2 Serial1
192.168.4.1/32Direct00127.0.0.1 LoopBack0
192.168.4.2/32Direct00192.168.4.2 Serial1
[r2]dis ip rou
Routing Tables:
Destination/MaskProtoPrefMetricNexthopInterface
127.0.0.0/8Direct00127.0.0.1 LoopBack0
127.0.0.1/32Direct00127.0.0.1 LoopBack0
192.168.1.0/24Static600192.168.4.1 Serial1
192.168.2.0/24Direct00192.168.2.1 Ethernet0
192.168.2.1/32Direct00127.0.0.1 LoopBack0
192.168.4.0/24Direct00192.168.4.1 Serial1
192.168.4.1/32Direct00192.168.4.1 Serial1
192.168.4.2/32Direct00127.0.0.1 LoopBack0
2.Back interface备份接口(适用在链路条件相同的两个链路)
备份接口是指有两条同样好的链路可以提供给我们走,为了防止单点故障给我们带来不便,我们把其中一条作为主链路一条作为备份链路,当然,这种链路的前提是计费按照流量来计算。
案例拓扑:
实验原理:(huawei 2621路由器)
Se0----se0作为主链路使用ospf
Se1----se1作为备份链路同样使用ospf
在主链路接口下配置它的备份接口即可
进入主接口把它down掉来模拟主链路出现故障
参考配置:
[r1]dis cu
Now create configuration...
Current configuration
!
version 1.74
sysname r1
firewall enable
aaa-enable
aaa accounting-scheme optional
!
interface Aux0
async mode flow
link-protocol ppp
!
interface Ethernet0
loopback
ip address 192.168.1.1 255.255.255.0
ospf enable area 0.0.0.0
!
interface Ethernet1
!
interface Serial0
link-protocol ppp
standby interface Serial 1(设置主链路接口的备份接口)
standby timer enable-delay 5 (设置主接口故障后几秒后备份接口up)
standby timer disable-delay 5 (设置主接口up后几秒后备份接口down)
ip address 192.168.3.1 255.255.255.0
ospf enable area 0.0.0.0
!
interface Serial1
link-protocol ppp
ip address 192.168.4.1 255.255.255.0
ospf enable area 0.0.0.0
!
ospf enable
!
quit
!
Return
[r2]dis cu
Now create configuration...
Current configuration
!
version 1.74
sysname r2
undo pos-server addr-switch
firewall enable
aaa-enable
aaa accounting-scheme optional
!
interface Aux0
async mode flow
link-protocol ppp
!
interface Ethernet0
loopback
ip address 192.168.2.1 255.255.255.0
ospf enable area 0.0.0.0
!
interface Ethernet1
!
interface Serial0
clock DTECLK1
link-protocol ppp
standby interface Serial 1(设置主链路接口的备份接口)
standby timer enable-delay 5 (设置主接口故障后几秒后备份接口up)
standby timer disable-delay 5 (设置主接口up后几秒后备份接口down)
ip address 192.168.3.2 255.255.255.0
ospf enable area 0.0.0.0
!
interface Serial1
clock DTECLK1
link-protocol ppp
ip address 192.168.4.2 255.255.255.0
ospf enable area 0.0.0.0
!
ospf enable
!
quit
!
Return
验证信息:
主链路正常工作时的路由表
[r1]dis ip rou
Routing Tables:
Destination/MaskProtoPrefMetricNexthopInterface
127.0.0.0/8Direct00127.0.0.1 LoopBack0
127.0.0.1/32Direct00127.0.0.1 LoopBack0
192.168.1.0/24Direct00192.168.1.1 Ethernet0
192.168.1.1/32Direct00127.0.0.1 LoopBack0
192.168.2.0/24OSPF101572192.168.3.2 Serial0
192.168.3.0/24Direct00192.168.3.2 Serial0
192.168.3.1/32Direct00127.0.0.1 LoopBack0
192.168.3.2/32Direct00192.168.3.2 Serial0
[r2]dis ip rou
Routing Tables:
Destination/MaskProtoPrefMetricNexthopInterface
127.0.0.0/8Direct00127.0.0.1 LoopBack0
127.0.0.1/32Direct00127.0.0.1 LoopBack0
192.168.1.0/24OSPF101572192.168.3.1 Serial0
192.168.2.0/24Direct00192.168.2.1 Ethernet0
192.168.2.1/32Direct00127.0.0.1 LoopBack0
192.168.3.0/24Direct00192.168.3.1 Serial0
192.168.3.1/32Direct00192.168.3.1 Serial0
192.168.3.2/32Direct00127.0.0.1 LoopBack0
主链路出现故障时的路由表
[r1]dis ip rou
Routing Tables:
Destination/MaskProtoPrefMetricNexthopInterface
127.0.0.0/8Direct00127.0.0.1 LoopBack0
127.0.0.1/32Direct00127.0.0.1 LoopBack0
192.168.1.0/24Direct00192.168.1.1 Ethernet0
192.168.1.1/32Direct00127.0.0.1 LoopBack0
192.168.2.0/24OSPF101572192.168.4.2 Serial1
192.168.4.0/24Direct00192.168.4.2 Serial1
192.168.4.1/32Direct00127.0.0.1 LoopBack0
192.168.4.2/32Direct00192.168.4.2 Serial1
[r2]dis ip rou
Routing Tables:
Destination/MaskProtoPrefMetricNexthopInterface
127.0.0.0/8Direct00127.0.0.1 LoopBack0
127.0.0.1/32Direct00127.0.0.1 LoopBack0
192.168.1.0/24OSPF101572192.168.4.1 Serial1
192.168.2.0/24Direct00192.168.2.1 Ethernet0
192.168.2.1/32Direct00127.0.0.1 LoopBack0
192.168.4.0/24Direct00192.168.4.1 Serial1
192.168.4.1/32Direct00192.168.4.1 Serial1
192.168.4.2/32Direct00127.0.0.1 LoopBack0
3.Mp ppp捆绑(旨在增加链路带宽)
MP是Multi-Link PPP的缩写,是将多个物理链路的PPP捆绑在同一个逻辑端口,旨在增加链路的带宽,只要是支持PPP的物理链路都可以启用MP,互相捆绑在同一个逻辑端口Virtual-Template口。MP允许将IP等网络层的报文进行碎片处理,将碎片的报文通过多个链路传输,同时抵达同一个目的地,以求汇总所有链路的带宽。
案例拓扑:
实验原理:(huawei 2621路由器)
将se0、se1捆绑起来形成两个逻辑端口Virtual-Template1和Virtual-Template2
参考配置:
[r1]dis cu
Now create configuration...
Current configuration
!
version 1.74
sysname r1
firewall enable
aaa-enable
aaa accounting-scheme optional
!
interface Aux0
async mode flow
link-protocol ppp
!
interface Ethernet0
loopback
ip address 192.168.1.1 255.255.255.0
!
interface Ethernet1
!
interface Serial0
link-protocol ppp
ppp mp(进端口启动mp)
ppp mp interface Virtual-Template1(把se0加入Virtual-Template1)
!
interface Serial1
link-protocol ppp
ppp mp(进端口启动mp)
ppp mp interface Virtual-Template1(把se1加入Virtual-Template1)
!
interface Virtual-Template1
link-protocol ppp
ip address 192.168.3.1 255.255.255.0
!
voice-setup
!
subscriber-line 0
!
subscriber-line 1
!
quit
!
quit
ip route-static 192.168.2.0 255.255.255.0 192.168.3.2 preference 60
!
return
[r2]dis cu
Now create configuration...
Current configuration
!
version 1.74
sysname r2
undo pos-server addr-switch
firewall enable
aaa-enable
aaa accounting-scheme optional
!
interface Aux0
async mode flow
link-protocol ppp
!
interface Ethernet0
loopback
ip address 192.168.2.1 255.255.255.0
!
interface Ethernet1
!
interface Serial0
clock DTECLK1
link-protocol ppp
ppp mp(进端口启动mp)
ppp mp interface Virtual-Template2(把se0加入Virtual-Template2)
shutdown
!
interface Serial1
clock DTECLK1
link-protocol ppp
ppp mp(进端口启动mp)
ppp mp interface Virtual-Template2(把se1加入Virtual-Template2)
interface Virtual-Template2
link-protocol ppp
ip address 192.168.3.2 255.255.255.0
!
quit
ip route-static 192.168.1.0 255.255.255.0 192.168.3.1 preference 60
!
Return
验证信息:
路由表信息
[r1]dis ip rou
Routing Tables:
Destination/MaskProtoPrefMetricNexthopInterface
127.0.0.0/8Direct00 127.0.0.1 LoopBack0
127.0.0.1/32Direct00127.0.0.1 LoopBack0
192.168.1.0/24Direct00192.168.1.1 Ethernet0
192.168.1.1/32Direct00127.0.0.1 LoopBack0
192.168.2.0/24Static600192.168.3.2 Virtual-Template1
192.168.3.0/24Direct00192.168.3.1 Virtual-Template1
192.168.3.1/32Direct00127.0.0.1 LoopBack0
192.168.3.2/32Direct00192.168.3.1 Virtual-Template1
[r2]dis ip rou
Routing Tables:
Destination/MaskProtoPrefMetricNexthopInterface
127.0.0.0/8Direct00127.0.0.1 LoopBack0
127.0.0.1/32Direct00127.0.0.1 LoopBack0
192.168.1.0/24Static600192.168.3.1 Virtual-Template2
192.168.2.0/24Direct00192.168.2.1 Ethernet0
192.168.2.1/32Direct00127.0.0.1 LoopBack0
192.168.3.0/24Direct00192.168.3.2 Virtual-Template2
192.168.3.1/32Direct00192.168.3.2 Virtual-Template2
192.168.3.2/32Direct 00127.0.0.1 LoopBack0
[r1]ping ip -a 192.168.1.1 192.168.2.1
PING 192.168.2.1: 56data bytes, press CTRL_C to break
Reply from 192.168.2.1: bytes=56 Sequence=0 ttl=255 time = 27 ms
Reply from 192.168.2.1: bytes=56 Sequence=1 ttl=255 time = 27 ms
Reply from 192.168.2.1: bytes=56 Sequence=2 ttl=255 time = 27 ms
Reply from 192.168.2.1: bytes=56 Sequence=3 ttl=255 time = 27 ms
Reply from 192.168.2.1: bytes=56 Sequence=4 ttl=255 time = 27 ms
--- 192.168.2.1 ping statistics ---
5 packets transmitted
5 packets received
0.00% packet loss
round-trip min/avg/max = 27/27/27 ms