Example for Configuring IPv4 Floating Static Routes

IPv4 Floating static routes can be used for the static route backup.

Networking Requirements

Figure 1 shows the IPv4 addresses and masks of each router interface and a host. Two IPv4 static routes to 10.1.5.0/24 are configured on Device A. The primary static route passes through Device B, and the floating static route passes through Device C.

Figure 1 Networking for configuring IPv4 floating static routes

Interfaces 1 through 3 in this example represent GE 0/1/1, GE 0/1/2, and GE 0/1/3, respectively.

Precautions

When configuring an IPv4 floating static route, a next-hop address of this route must be specified if the outbound interface is of the broadcast type.

Configuration Roadmap

The configuration roadmap is as follows:

Configure an IPv4 address for each interface of each router.
On Devices B and C, configure IPv4 static routes to 10.1.5.0/24.
On Device A, configure IPv4 static routes to 10.1.3.0/24 and 10.1.4.0/24.
On Device A, configure two IPv4 static routes to 10.1.5.0/24 with different priorities.
On Device D, configure IPv4 static routes to 10.1.1.0/24 and 10.1.2.0/24 so that routers can communicate.

Data Preparation

To complete the configuration, you need the following data:

On Device A, priority values of two static routes (60 for the one with 10.1.1.2 as the next hop address and 100 for the one with 10.1.2.2 as the next-hop address)

Procedure

Configure an IP address for each interface. For configuration details, see Configuration File in this section.

Configure IPv4 static routes.

# Configure IPv4 static routes on Device B.

[~DeviceB] ip route-static 10.1.5.0 24 10.1.3.2
[*DeviceB] commit

# Configure IPv4 static routes on Device C.

[~DeviceC] ip route-static 10.1.5.0 24 10.1.4.2
[*DeviceC] commit

# Configure IPv4 static routes on Device A.

[~DeviceA] ip route-static 10.1.3.0 24 10.1.1.2
[*DeviceA] ip route-static 10.1.4.0 24 10.1.2.2
[*DeviceA] ip route-static 10.1.5.0 24 10.1.1.2
[*DeviceA] ip route-static 10.1.5.0 24 10.1.2.2 preference 100
[*DeviceA] commit

# Configure IPv4 static routes on Device D.

[~DeviceD] ip route-static 10.1.1.0 24 10.1.3.1
[*DeviceD] ip route-static 10.1.2.0 24 10.1.4.1
[*DeviceD] commit

Verify the configuration.

# View information about static routes in the IP routing table of Device A.

<DeviceA> display ip routing-table protocol static
Route Flags: R - relay, D - download to fib, T - to vpn-instance, B - black hole route
------------------------------------------------------------------------------
_public_ Routing Table : Static

         Destinations : 3        Routes : 3        Configured Routes : 3      
Static routing table status : <Active>
         Destinations : 3        Routes : 3         

Destination/Mask    Proto  Pre  Cost        Flags NextHop         Interface

       10.1.3.0/24  Static 60   0             RD 10.1.1.2        GigabitEthernet0/1/1
       10.1.4.0/24  Static 60   0             RD 10.1.2.2        GigabitEthernet0/1/2
    10.1.5.0/24  Static 60   0             RD 10.1.1.2        GigabitEthernet0/1/1

Static routing table status : <Inactive>
         Destinations : 0        Routes : 0

# Use the tracert command to check the connectivity on Device A.

<DeviceA> tracert 10.1.5.1
  traceroute to  10.1.5.1(10.1.5.1), max hops: 30 ,packet length: 40
 1 10.1.1.2 90 ms  1 ms  1 ms
 2 10.1.5.1 4 ms  1 ms  2 ms

# Run the shutdown command on GE 0/1/1 of Device A to simulate a link fault.

[~DeviceA] interface GigabitEthernet 0/1/1 
[~DeviceA-GigabitEthernet0/1/1] shutdown 
[~DeviceA-GigabitEthernet0/1/1] commit

# View information about static routes in the IP routing table of Device A. The route to 10.1.5.0/24 switches to the floating static route with next hop 10.1.2.2.

[~DeviceA-GigabitEthernet0/1/1] quit
[~DeviceA] quit
<DeviceA> display ip routing-table protocol static
Route Flags: R - relay, D - download to fib, T - to vpn-instance, B - black hole route
------------------------------------------------------------------------------
_public_ Routing Table : Static

         Destinations : 2        Routes : 2        Configured Routes : 2      
Static routing table status : <Active>
         Destinations : 2        Routes : 2         

Destination/Mask    Proto  Pre  Cost        Flags NextHop         Interface

       10.1.4.0/24  Static 60   0             RD 10.1.2.2        GigabitEthernet0/1/2
    10.1.5.0/24  Static 100   0             RD 10.1.2.2        GigabitEthernet0/1/2

Static routing table status : <Inactive>
         Destinations : 0        Routes : 0

# Use the tracert command to check the connectivity on Device A.

<DeviceA> tracert 10.1.5.1
  traceroute to  10.1.5.1(10.1.5.1), max hops: 30 ,packet length: 40
 1 10.1.2.2 100 ms  1 ms  1 ms
 2 10.1.5.1 5 ms  1 ms  2 ms

Configuration Files

Device A configuration file

#
sysname DeviceA
#
interface GigabitEthernet0/1/1
 undo shutdown
 ip address 10.1.1.1 255.255.255.0
#
interface GigabitEthernet0/1/2
 undo shutdown
 ip address 10.1.2.1 255.255.255.0
#
ip route-static 10.1.3.0 24 10.1.1.2
ip route-static 10.1.4.0 24 10.1.2.2
ip route-static 10.1.5.0 24 10.1.1.2
ip route-static 10.1.5.0 24 10.1.2.2 preference 100
#
return

Device B configuration file

#
sysname DeviceB
#
interface GigabitEthernet0/1/1
 undo shutdown
 ip address 10.1.1.2 255.255.255.0
#
interface GigabitEthernet0/1/2
 undo shutdown
 ip address 10.1.3.1 255.255.255.0
#
ip route-static 10.1.5.0 24 10.1.3.2
#
return

Device C configuration file

#
sysname DeviceC
#
interface GigabitEthernet0/1/1
 undo shutdown
 ip address 10.1.2.2 255.255.255.0
#
interface GigabitEthernet0/1/2
 undo shutdown
 ip address 10.1.4.1 255.255.255.0
#
ip route-static 10.1.5.0 24 10.1.4.2
#
return

Device D configuration file

#
sysname DeviceD
#
interface GigabitEthernet0/1/1
 undo shutdown
 ip address 10.1.3.2 255.255.255.0
#
interface GigabitEthernet0/1/2
 undo shutdown
 ip address 10.1.4.2 255.255.255.0
#
interface GigabitEthernet0/1/3
 undo shutdown
 ip address 10.1.5.1 255.255.255.0
#
ip route-static 10.1.1.0 24 10.1.3.1
ip route-static 10.1.2.0 24 10.1.4.1
#
return