设置了静态路由的优先级，怎样实现断线自动切换到优先级低的静态路由

1.1.2  1.2配置需求及实现的效果

SW1、SW2、SW3和SW4连接了2.2.2.0/24和3.3.3.0/24两个网段，在交换机上配置静态路由以实现两个网段的互通，并配置路由备份以提高网络的可靠性。

SW2上配置环回口L0模拟2.2.2.0/24网段内的主机，在SW2上存在两条到达3.3.3.0/24网段的静态路由，下一跳分别为SW1和SW4，这两条静态路由形成备份，其中：

·     下一跳为SW1的静态路由优先级高，作为主路由。该路由可达时，SW2通过SW1将报文转发到3.3.3.0/24网段。

·     下一跳为SW4的静态路作为备份路由。

·     在SW2上通过静态路由、Track与NQA联动，实时判断主路由是否可达。当主路由不可达时，备份路由生效，SW2通过SW4将报文转发到3.3.3.0/24网段。

同样地，SW3上配置环回接口L0模拟3.3.3.0/24网段内的主机，在SW3D上存在两条到达2.2.2.0/24网段的静态路由，下一跳分别为SW1和SW4。这两条静态路由形成备份，其中：

·     下一跳为SW1的静态路由优先级高，作为主路由。该路由可达时，SW3通过SW1将报文转发到2.2.2.0/24网段。

·     下一跳为SW4的静态路作为备份路由。

·     在SW3上通过静态路由、Track与NQA联动，实时判断主路由是否可达。当主路由不可达时，备份路由生效，SW3通过SW4将报文转发到2.2.2.0/24网段。

2 组网图

3 配置步骤

一．交换机vlan和ip地址基本配置

#在SW1上关闭生成树

system-view

System View: return to User View with Ctrl+Z.

[H3C]undo stp global enable

#创建vlan 4

[H3C]vlan 4

[H3C-vlan4]quit

#配置vlan 1和vlan 4虚接口IP地址

[H3C]interface Vlan-interface 1

[H3C-Vlan-interface1] ip address 13.13.13.1 255.255.255.0

[H3C-Vlan-interface1]quit

[H3C]interface Vlan-interface 4

[H3C-Vlan-interface4] ip address 12.12.12.1 255.255.255.0

[H3C-Vlan-interface4]quit

#将端口2换分到vlan 4，端口1默认属于vlan 1

[H3C]interface GigabitEthernet 1/0/2

[H3C-GigabitEthernet1/0/2] port access vlan 4

[H3C-GigabitEthernet1/0/2]quit

#在SW2上关闭生成树

system-view

System View: return to User View with Ctrl+Z.

[H3C]undo stp global enable

#创建环回接口LoopBack 0用来模拟主机，地址是2.2.2.2/24

[H3C]interface LoopBack 0

[H3C-LoopBack0]ip address 2.2.2.2 255.255.255.0

[H3C-LoopBack0]quit

#创建vlan 3、4，并分别配置IP地址。

[H3C]vlan 3

[H3C-vlan3]quit

[H3C]interface Vlan-interface 3

[H3C-Vlan-interface3] ip address 24.24.24.2 255.255.255.0

[H3C-Vlan-interface3]quit

[H3C]vlan 4

[H3C-vlan4]quit

[H3C]interface Vlan-interface 4

[H3C-Vlan-interface4] ip address 12.12.12.2 255.255.255.0

[H3C-Vlan-interface4]quit

#将端口1换分到vlan 4，端口2划分到vlan 3

[H3C]interface GigabitEthernet 1/0/1

[H3C-GigabitEthernet1/0/1] port access vlan 4

[H3C-GigabitEthernet1/0/1]quit

[H3C]interface GigabitEthernet 1/0/2

[H3C-GigabitEthernet1/0/2] port access vlan 3

[H3C-GigabitEthernet1/0/2]quit

#在SW3上关闭生成树

system-view

System View: return to User View with Ctrl+Z.

[H3C]undo stp global enable

#创建环回接口LoopBack 0用来模拟主机，地址是3.3.3.3/24

[H3C]interface LoopBack 0

[H3C-LoopBack0]ip address 3.3.3.3 255.255.255.0

[H3C-LoopBack0]quit

#创建vlan 2，并分别配置vlan 1和vlan 2的IP地址

[H3C]vlan 2

[H3C-vlan2]quit

[H3C]interface Vlan-interface 1

[H3C-Vlan-interface1] ip address 13.13.13.3 255.255.255.0

[H3C-Vlan-interface1]quit

[H3C]interface Vlan-interface 2

[H3C-Vlan-interface2] ip address 34.34.34.3 255.255.255.0

[H3C-Vlan-interface2]quit

#将端口1换分到vlan 2，端口2默认属于vlan 1

[H3C]interface GigabitEthernet 1/0/1

[H3C-GigabitEthernet1/0/1] port access vlan 2

[H3C-GigabitEthernet1/0/1]quit

#在SW4上关闭生成树

system-view

System View: return to User View with Ctrl+Z.

[H3C]undo stp global enable

#创建vlan 2、3，并分别配置IP地址

[H3C]vlan 2

[H3C-vlan2]quit

[H3C]interface Vlan-interface 2

[H3C-Vlan-interface2] ip address 34.34.34.4 255.255.255.0

[H3C-Vlan-interface2]quit

[H3C]vlan 3

[H3C-vlan3]quit

[H3C]interface Vlan-interface 3

[H3C-Vlan-interface3] ip address 24.24.24.4 255.255.255.0

[H3C-Vlan-interface3]quit

#将端口1换分到vlan 3，端口2划分到vlan 2

[H3C]interface GigabitEthernet 1/0/1

[H3C-GigabitEthernet1/0/1] port access vlan 3

[H3C-GigabitEthernet1/0/1]quit

[H3C]interface GigabitEthernet 1/0/2

[H3C-GigabitEthernet1/0/2] port access vlan 2

[H3C-GigabitEthernet1/0/2]quit

二．链路检测配置

【SW1】

#SW1配置到2.2.2.0和3.3.3.0网段的静态路由

[H3C]ip route-static 2.2.2.0 24 12.12.12.2

[H3C]ip route-static 3.3.3.0 24 13.13.13.3

【SW2】

# 配置到达3.3.3.0/24网段的静态路由：下一跳地址为12.12.12.1，优先级为缺省值60，该路由与Track项1关联。

system-view

[H3C] ip route-static 3.3.3.0 24 12.12.12.1 track 1

# 配置到达3.3.3.0/24网段的静态路由：下一跳地址为24.24.24.4，优先级为80。

[H3C] ip route-static 3.3.3.0 24 24.24.24.4 preference 80

# 配置到达13.13.13.0的静态路由：下一跳地址为12.12.12.1。

[H3C]ip route-static 13.13.13.0 24 12.12.12.1

# 配置到达34.34.34.0的静态路由：下一跳地址为24.24.24.4。

[H3C]ip route-static 34.34.34.0 24 24.24.24.4

# 创建管理员名为admin、操作标签为test的NQA测试组。

[H3C] nqa entry admin test

# 配置测试类型为ICMP-echo。

[H3C-nqa-admin-test] type icmp-echo

# 配置测试的目的地址为13.13.13.3，下一跳地址为12.12.12.1，以便通过NQA检测Switch 2－Switch 2－Switch 3这条路径的连通性。

[H3C-nqa-admin-test-icmp-echo] destination ip 13.13.13.3

[H3C-nqa-admin-test-icmp-echo] next-hop ip 12.12.12.1

# 配置测试频率为100ms。

[H3C-nqa-admin-test-icmp-echo] frequency 100

# 配置联动项1（连续失败5次触发联动）。

[H3C-nqa-admin-test-icmp-echo] reaction 1 checked-element probe-fail threshold-type consecutive 5 action-type trigger-only

[H3C-nqa-admin-test-icmp-echo] quit

# 启动探测。

[H3C] nqa schedule admin test start-time now lifetime forever

# 配置Track项1，关联NQA测试组（管理员为admin，操作标签为test）的联动项1。

[H3C] track 1 nqa entry admin test reaction 1

【SW3】

# 配置到达2.2.2.0/24网段的静态路由：下一跳地址为13.13.13.1，优先级为缺省值60，该路由与Track项1关联。

system-view

[H3C] ip route-static 2.2.2.0 24 13.13.13.1 track 1

# 配置到达2.2.2.0/24网段的静态路由：下一跳地址为34.34.34.4，优先级为80。

[H3C] ip route-static 2.2.2.0 24 34.34.34.4 preference 80

# 配置到达12.12.12.0的静态路由：下一跳地址为13.13.13.1。

[H3C] ip route-static 12.12.12.0 24 13.13.13.1

# 配置到达24.24.24.0的静态路由：下一跳地址为34.34.34.4。

[H3C] ip route-static 24.24.24.0 24 34.34.34.4

# 创建管理员名为admin、操作标签为test的NQA测试组。

[H3C] nqa entry admin test

# 配置测试类型为ICMP-echo。

[H3C-nqa-admin-test] type icmp-echo

# 配置测试的目的地址为12.12.12.2，下一跳地址为13.13.13.1，以便通过NQA检测Switch 2－Switch 2－Switch 3这条路径的连通性。

[H3C-nqa-admin-test-icmp-echo] destination ip 12.12.12.2

[H3C-nqa-admin-test-icmp-echo] next-hop ip 13.13.13.1

# 配置测试频率为100ms。

[H3C-nqa-admin-test-icmp-echo] frequency 100

# 配置联动项1（连续失败5次触发联动）。

[H3C-nqa-admin-test-icmp-echo] reaction 1 checked-element probe-fail threshold-type consecutive 5 action-type trigger-only

[H3C-nqa-admin-test-icmp-echo] quit

# 启动探测。

[H3C] nqa schedule admin test start-time now lifetime forever

# 配置Track项1，关联NQA测试组（管理员为admin，操作标签为test）的联动项1。

[H3C] track 1 nqa entry admin test reaction 1

【SW4】

#SW1配置到2.2.2.0和3.3.3.0网段的静态路由

[H3C]ip route-static 2.2.2.0 24 24.24.24.2

[H3C]ip route-static 3.3.3.0 24 34.34.34.3

4 验证配置

 # 显示SW2上Track项的信息：

[H3C]display track all

Track ID: 1

  State: Positive

  Duration: 0 days 0 hours 1 minutes 18 seconds

  Tracked object type: NQA

  Notification delay: Positive 0, Negative 0 (in seconds)

  Tracked object:

    NQA entry: admin test

    Reaction: 1

    Remote IP/URL: 13.13.13.3

    Local IP: --

    Interface: --

#查看SW2上的路由表：

[H3C]display ip routing-table

Destinations : 23       Routes : 23

Destination/Mask   Proto   Pre Cost        NextHop         Interface

0.0.0.0/32         Direct  0   0           127.0.0.1       InLoop0

2.2.2.0/24         Direct  0   0           2.2.2.2         Loop0

2.2.2.0/32         Direct  0   0           2.2.2.2         Loop0

2.2.2.2/32         Direct  0   0           127.0.0.1       InLoop0

2.2.2.255/32       Direct  0   0           2.2.2.2         Loop0

3.3.3.0/24         Static  60  0           12.12.12.1      Vlan4

12.12.12.0/24      Direct  0   0           12.12.12.2      Vlan4

12.12.12.0/32      Direct  0   0           12.12.12.2      Vlan4

12.12.12.2/32      Direct  0   0           127.0.0.1       InLoop0

12.12.12.255/32    Direct  0   0           12.12.12.2      Vlan4

13.13.13.0/24      Static  60  0           12.12.12.1      Vlan4

24.24.24.0/24      Direct  0   0           24.24.24.2      Vlan3

24.24.24.0/32      Direct  0   0           24.24.24.2      Vlan3

24.24.24.2/32      Direct  0   0           127.0.0.1       InLoop0

24.24.24.255/32    Direct  0   0           24.24.24.2      Vlan3

34.34.34.0/24      Static  60  0           24.24.24.4      Vlan3

127.0.0.0/8        Direct  0   0           127.0.0.1       InLoop0

127.0.0.0/32       Direct  0   0           127.0.0.1       InLoop0

127.0.0.1/32       Direct  0   0           127.0.0.1       InLoop0

127.255.255.255/32 Direct  0   0           127.0.0.1       InLoop0

224.0.0.0/4        Direct  0   0           0.0.0.0         NULL0

224.0.0.0/24       Direct  0   0           0.0.0.0         NULL0

255.255.255.255/32 Direct  0   0           127.0.0.1       InLoop0

#以上NQA测试的结果为主路由可达（Track项状态为Positive），访问3.3.3.0/24网段路径是SW2-SW1-SW3。

#将SW1的2号端口shutdown

[H3C]int GigabitEthernet 1/0/2

[H3C-GigabitEthernet1/0/2]shutdown

# 显示SW2上Track项的信息：

[H3C]display track all

Track ID: 1

  State: Negative

  Duration: 0 days 0 hours 0 minutes 10 seconds

  Tracked object type: NQA

  Notification delay: Positive 0, Negative 0 (in seconds)

  Tracked object:

    NQA entry: admin test

    Reaction: 1

    Remote IP/URL: 13.13.13.3

    Local IP: --

Interface: --

#查看SW2上的路由表

[H3C]display ip routing-table

Destinations : 18       Routes : 18

Destination/Mask   Proto   Pre Cost        NextHop         Interface

0.0.0.0/32         Direct  0   0           127.0.0.1       InLoop0

2.2.2.0/24         Direct  0   0           2.2.2.2         Loop0

2.2.2.0/32         Direct  0   0           2.2.2.2         Loop0

2.2.2.2/32         Direct  0   0           127.0.0.1       InLoop0

2.2.2.255/32       Direct  0   0           2.2.2.2         Loop0

3.3.3.0/24         Static  80  0           24.24.24.4      Vlan3

24.24.24.0/24      Direct  0   0           24.24.24.2      Vlan3

24.24.24.0/32      Direct  0   0           24.24.24.2      Vlan3

24.24.24.2/32      Direct  0   0           127.0.0.1       InLoop0

24.24.24.255/32    Direct  0   0           24.24.24.2      Vlan3

34.34.34.0/24      Static  60  0           24.24.24.4      Vlan3

127.0.0.0/8        Direct  0   0           127.0.0.1       InLoop0

127.0.0.0/32       Direct  0   0           127.0.0.1       InLoop0

127.0.0.1/32       Direct  0   0           127.0.0.1       InLoop0

127.255.255.255/32 Direct  0   0           127.0.0.1       InLoop0

224.0.0.0/4        Direct  0   0           0.0.0.0         NULL0

224.0.0.0/24       Direct  0   0           0.0.0.0         NULL0

255.255.255.255/32 Direct  0   0           127.0.0.1       InLoop0

#NQA测试的结果为主路由不可达（Track项状态为Negative），则备份路由生效，访问3.3.3.0/24网段路径是SW2-SW4-SW3。出现故障后，2.2.2.2到3.3.3.3之间仍然可以通信：

[H3C]ping -a 2.2.2.2 3.3.3.3

Ping 3.3.3.3 (3.3.3.3) from 2.2.2.2: 56 data bytes, press CTRL_C to break

56 bytes from 3.3.3.3: icmp_seq=0 ttl=254 time=4.000 ms

56 bytes from 3.3.3.3: icmp_seq=1 ttl=254 time=3.000 ms

56 bytes from 3.3.3.3: icmp_seq=2 ttl=254 time=1.000 ms

56 bytes from 3.3.3.3: icmp_seq=3 ttl=254 time=1.000 ms

56 bytes from 3.3.3.3: icmp_seq=4 ttl=254 time=1.000 ms

--- Ping statistics for 3.3.3.3 ---

5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss

round-trip min/avg/max/std-dev = 1.000/2.000/4.000/1.265 ms

[H3C]%May 29 10:21:41:325 2019 H3C PING/6/PING_STATISTICS: Ping statistics for 3.3.3.3: 5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss, round-trip min/avg/max/std-dev = 1.000/2.000/4.000/1.265 ms.