Contents

Configuring static routing· 1

About static routes· 1

Configuring a static route· 1

Deleting static routes· 1

Configuring BFD for static routes· 2

About BFD·· 2

Configuring BFD control packet mode· 2

Configuring BFD echo packet mode· 3

Configuring static route FRR· 4

About static route FRR· 4

Restrictions and guidelines for static route FRR· 4

Configuring static route FRR by specifying a backup next hop· 4

Configuring static route FRR to automatically select a backup next hop· 5

Enabling BFD echo packet mode for static route FRR· 5

Verifying and maintaining static routing· 6

Static route configuration examples· 6

Example: Configuring basic static routes· 6

Example: Configuring BFD for static routes (direct next hop) 8

Example: Configuring BFD for static routes (indirect next hop) 10

Example: Configuring static route FRR· 13

Configuring a default route· 16

 

Configuring static routing

About static routes

Static routes are manually configured. If a network's topology is simple, you only need to configure static routes for the network to work correctly.

Static routes cannot adapt to network topology changes. If a fault or a topological change occurs in the network, the network administrator must modify the static routes manually.

Configuring a static route

1.     Enter system view.

system-view

2.     Configure a static route.

Public network:

ip route-static dest-address { mask-length | mask } { interface-type interface-number [ next-hop-address ] | next-hop-address [ recursive-lookup { host-route | longest-match } ] | vpn-instance d-vpn-instance-name next-hop-address [ recursive-lookup { host-route | longest-match } ] } [ permanent ] [ preference preference ] [ tag tag-value ] [ description text ]

By default, no static route is configured.

VPN:

ip route-static vpn-instance s-vpn-instance-name dest-address { mask-length | mask } { interface-type interface-number [ next-hop-address [ nexthop-index index-string ] ] | next-hop-address [ nexthop-index index-string ] [ recursive-lookup { host-route | longest-match } ] [ public ] | vpn-instance d-vpn-instance-name next-hop-address [ nexthop-index index-string ] [ recursive-lookup { host-route | longest-match } ] } [ permanent ] [ preference preference ] [ tag tag-value ] [ description text ]

By default, no static route is configured.

3.     (Optional.) Enable periodic sending of ARP requests to the next hops of static routes.

ip route-static arp-request interval interval

By default, the device does not send ARP requests to the next hops of static routes.

4.     (Optional.) Configure the default preference for static routes.

ip route-static default-preference default-preference

The default setting is 60.

Deleting static routes

About this task

To delete a static route, use the undo ip route-static command. To delete all static routes including the default route, use the delete static-routes all command.

Procedure

1.     Enter system view.

system-view

2.     Delete all static routes.

Public network:

delete static-routes all

VPN:

delete vpn-instance vpn-instance-name static-routes all

 

CAUTION: This command might interrupt network communication and cause packet forwarding failure. Before executing the command, make sure you fully understand the potential impact on the network.

 

Configuring BFD for static routes

	IMPORTANT: Enabling BFD for a flapping route could worsen the situation.

 

About BFD

BFD provides a general-purpose, standard, medium-, and protocol-independent fast failure detection mechanism. It can uniformly and quickly detect the failures of the bidirectional forwarding paths between two routers for protocols, such as routing protocols.

For more information about BFD, see High Availability Configuration Guide.

Configuring BFD control packet mode

About this task

This mode uses BFD control packets to detect the status of a link bidirectionally at a millisecond level.

BFD control packet mode can be applied to static routes with a direct next hop or with an indirect next hop.

Restrictions and guidelines for BFD control packet mode

If you use BFD control packet mode at the local end, you must use this mode also at the peer end.

Configuring BFD control packet mode for a static route (direct next hop)

1.     Enter system view.

system-view

2.     Configure BFD control packet mode for a static route.

Public network:

ip route-static dest-address { mask-length | mask } interface-type interface-number next-hop-address bfd control-packet [ preference preference ] [ tag tag-value ] [ description text ]

VPN:

ip route-static vpn-instance s-vpn-instance-name dest-address { mask-length | mask } interface-type interface-number next-hop-address bfd control-packet [ preference preference ] [ tag tag-value ] [ description text ]

By default, BFD control packet mode for a static route is not configured.

Configuring BFD control packet mode for a static route (indirect next hop)

1.     Enter system view.

system-view

2.     Configure BFD control packet mode for a static route.

Public network:

ip route-static dest-address { mask-length | mask } { next-hop-address bfd control-packet bfd-source ip-address | vpn-instance d-vpn-instance-name next-hop-address bfd control-packet bfd-source ip-address } [ preference preference ] [ tag tag-value ] [ description text ]

VPN:

ip route-static vpn-instance s-vpn-instance-name dest-address { mask-length | mask } { next-hop-address bfd control-packet bfd-source ip-address | vpn-instance d-vpn-instance-name next-hop-address bfd control-packet bfd-source ip-address } [ preference preference ] [ tag tag-value ] [ description text ]

By default, BFD control packet mode for a static route is not configured.

Configuring BFD echo packet mode

About this task

With BFD echo packet mode enabled for a static route, the output interface sends BFD echo packets to the destination device, which loops the packets back to test the link reachability.

Restrictions and guidelines

You do not need to configure BFD echo packet mode at the peer end.

Do not use BFD for a static route with the output interface in spoofing state.

Procedure

1.     Enter system view.

system-view

2.     (Optional.) Configure the source address of echo packets.

bfd echo-source-ip ip-address

By default, the source address of echo packets is not configured.

As a best practice to avoid network congestion caused by excessive ICMP redirect packets from the peer, use this command. Make sure the source IPv4 address is not on the subnet of any interfaces on the device.

For more information about this command, see BFD in High Availability Command Reference.

3.     Configure BFD echo packet mode for a static route.

Public network:

ip route-static dest-address { mask-length | mask } interface-type interface-number next-hop-address bfd echo-packet [ preference preference ] [ tag tag-value ] [ description text ]

VPN:

ip route-static vpn-instance s-vpn-instance-name dest-address { mask-length | mask } interface-type interface-number next-hop-address bfd echo-packet [ preference preference ] [ tag tag-value ] [ description text ]

By default, BFD echo packet mode for a static route is not configured.

Configuring static route FRR

About static route FRR

A link or router failure on a path can cause packet loss. Static route fast reroute (FRR) enables fast rerouting to minimize the impact of link or node failures.

Figure 1 Network diagram

 

As shown in Figure 1, upon a link failure, packets are directed to the backup next hop to avoid traffic interruption. You can either specify a backup next hop for FRR or enable FRR to automatically select a backup next hop (which must be configured in advance).

Restrictions and guidelines for static route FRR

·     Do not use static route FRR and BFD (for a static route) at the same time.

·     Equal-cost routes do not support static route FRR.

·     Besides the configured static route for FRR, the device must have another route to reach the destination.

When the state of the primary link (with Layer 3 interfaces staying up) changes from bidirectional to unidirectional or down, static route FRR quickly redirects traffic to the backup next hop. When the Layer 3 interfaces of the primary link are down, static route FRR temporarily redirects traffic to the backup next hop. In addition, the device searches for another route to reach the destination and redirects traffic to the new path if a route is found. If no route is found, traffic interruption occurs.

Configuring static route FRR by specifying a backup next hop

Restrictions and guidelines

A static route does not take effect when the backup output interface is unavailable.

To change the backup output interface or next hop, you must first remove the current setting. The backup output interface and next hop must be different from the primary output interface and next hop.

Procedure

1.     Enter system view.

system-view

2.     Configure static route FRR.

Public network:

ip route-static dest-address { mask-length | mask } interface-type interface-number [ next-hop-address [ backup-interface interface-type interface-number [ backup-nexthop backup-nexthop-address ] ] ] [ permanent ] [ preference preference ] [ tag tag-value ] [ description text ]

VPN:

ip route-static vpn-instance s-vpn-instance-name dest-address { mask-length | mask } interface-type interface-number [ next-hop-address [ backup-interface interface-type interface-number [ backup-nexthop backup-nexthop-address ] ] ] [ permanent ] [ preference preference ] [ tag tag-value ] [ description text ]

By default, static route FRR is disabled.

Configuring static route FRR to automatically select a backup next hop

1.     Enter system view.

system-view

2.     Configure static route FRR to automatically select a backup next hop.

ip route-static fast-reroute auto

By default, static route FRR is disabled from automatically selecting a backup next hop.

Enabling BFD echo packet mode for static route FRR

About this task

By default, static route FRR uses ARP to detect primary link failures. Perform this task to enable static route FRR to use BFD echo packet mode for fast failure detection on the primary link.

Procedure

1.     Enter system view.

system-view

2.     (Optional.) Configure the source IP address of BFD echo packets.

bfd echo-source-ip ip-address

By default, the source IP address of BFD echo packets is not configured.

As a best practice to avoid network congestion caused by excessive ICMP redirect packets from the peer, use this command. Make sure the source IPv4 address is not on the subnet of any interfaces on the device.

For more information about this command, see BFD in High Availability Command Reference.

3.     Enable BFD echo packet mode for static route FRR.

ip route-static primary-path-detect bfd echo

By default, BFD echo packet mode for static route FRR is disabled.

Verifying and maintaining static routing

Perform display tasks in any view.

·     Display static route information.

display ip routing-table protocol static [ inactive | verbose ]

For more information about this command, see basic IP routing commands in Layer 3—IP Routing Command Reference.

·     Display static route next hop information.

display route-static nib [ nib-id ] [ verbose ]

·     Display static routing table information.

display route-static routing-table [ vpn-instance vpn-instance-name ] [ ip-address { mask-length | mask } ]

Static route configuration examples

Example: Configuring basic static routes

Network configuration

As shown in Figure 2, configure static routes on the switches for interconnections between any two hosts.

Figure 2 Network diagram

 

Prerequisites

Configure IP addresses for the interfaces as shown in Figure 2.

Procedure

1.     Configure static routes:

# Configure a default route on Switch A.

<SwitchA> system-view

[SwitchA] ip route-static 0.0.0.0 0.0.0.0 1.1.4.2

# Configure two static routes on Switch B.

<SwitchB> system-view

[SwitchB] ip route-static 1.1.2.0 255.255.255.0 1.1.4.1

[SwitchB] ip route-static 1.1.3.0 255.255.255.0 1.1.5.6

# Configure a default route on Switch C.

<SwitchC> system-view

[SwitchC] ip route-static 0.0.0.0 0.0.0.0 1.1.5.5

2.     Configure the default gateways of Host A, Host B, and Host C as 1.1.2.3, 1.1.6.1, and 1.1.3.1. (Details not shown.)

Verifying the configuration

# Display static routes on Switch A.

[SwitchA] display ip routing-table protocol static

 

Summary count : 1

 

Static Routing table status : <Active>

Summary count : 1

 

Destination/Mask    Proto  Pre  Cost         NextHop         Interface

0.0.0.0/0           Static 60   0            1.1.4.2         Vlan500

 

Static Routing table status : <Inactive>

Summary count : 0

# Display static routes on Switch B.

[SwitchB] display ip routing-table protocol static

 

Summary count : 2

 

Static Routing table status : <Active>

Summary count : 2

 

Destination/Mask    Proto  Pre  Cost         NextHop         Interface

1.1.2.0/24          Static 60   0            1.1.4.1         Vlan500

 

Static Routing table status : <Inactive>

Summary count : 0

# Use the ping command on Host B to test the reachability of Host A (Windows XP runs on the two hosts).

C:\Documents and Settings\Administrator>ping 1.1.2.2

 

Pinging 1.1.2.2 with 32 bytes of data:

 

Reply from 1.1.2.2: bytes=32 time=1ms TTL=126

Reply from 1.1.2.2: bytes=32 time=1ms TTL=126

Reply from 1.1.2.2: bytes=32 time=1ms TTL=126

Reply from 1.1.2.2: bytes=32 time=1ms TTL=126

 

Ping statistics for 1.1.2.2:

    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

    Minimum = 1ms, Maximum = 1ms, Average = 1ms

# Use the tracert command on Host B to test the reachability of Host A.

C:\Documents and Settings\Administrator>tracert 1.1.2.2

 

Tracing route to 1.1.2.2 over a maximum of 30 hops

 

  1    <1 ms    <1 ms    <1 ms  1.1.6.1

  2    <1 ms    <1 ms    <1 ms  1.1.4.1

  3     1 ms    <1 ms    <1 ms  1.1.2.2

 

Trace complete.

Example: Configuring BFD for static routes (direct next hop)

Network configuration

Configure the following, as shown in Figure 3:

·     Configure a static route to subnet 120.1.1.0/24 on Switch A.

·     Configure a static route to subnet 121.1.1.0/24 on Switch B.

·     Enable BFD for both routes.

·     Configure a static route to subnet 120.1.1.0/24 and a static route to subnet 121.1.1.0/24 on Switch C.

When the link between Switch A and Switch B through the Layer 2 switch fails, BFD can detect the failure immediately. Switch A then communicates with Switch B through Switch C.

Figure 3 Network diagram

 

Table 1 Interface and IP address assignment

Device	Interface	IP address
Switch A	VLAN-interface 10	12.1.1.1/24
Switch A	VLAN-interface 11	10.1.1.102/24
Switch B	VLAN-interface 10	12.1.1.2/24
Switch B	VLAN-interface 13	13.1.1.1/24
Switch C	VLAN-interface 11	10.1.1.100/24
Switch C	VLAN-interface 13	13.1.1.2/24

 

Prerequisites

Configure IP addresses for the interfaces as shown in Figure 3.

Procedure

# Configure static routes on Switch A and enable BFD control packet mode for the static route that traverses the Layer 2 switch.

<SwitchA> system-view

[SwitchA] interface vlan-interface 10

[SwitchA-vlan-interface10] bfd min-transmit-interval 500

[SwitchA-vlan-interface10] bfd min-receive-interval 500

[SwitchA-vlan-interface10] bfd detect-multiplier 9

[SwitchA-vlan-interface10] quit

[SwitchA] ip route-static 120.1.1.0 24 vlan-interface 10 12.1.1.2 bfd control-packet

[SwitchA] ip route-static 120.1.1.0 24 vlan-interface 11 10.1.1.100 preference 65

[SwitchA] quit

# Configure static routes on Switch B and enable BFD control packet mode for the static route that traverses the Layer 2 switch.

<SwitchB> system-view

[SwitchB] interface vlan-interface 10

[SwitchB-vlan-interface10] bfd min-transmit-interval 500

[SwitchB-vlan-interface10] bfd min-receive-interval 500

[SwitchB-vlan-interface10] bfd detect-multiplier 9

[SwitchB-vlan-interface10] quit

[SwitchB] ip route-static 121.1.1.0 24 vlan-interface 10 12.1.1.1 bfd control-packet

[SwitchB] ip route-static 121.1.1.0 24 vlan-interface 13 13.1.1.2 preference 65

[SwitchB] quit

# Configure static routes on Switch C.

<SwitchC> system-view

[SwitchC] ip route-static 120.1.1.0 24 13.1.1.1

[SwitchC] ip route-static 121.1.1.0 24 10.1.1.102

Verifying the configuration

# Display BFD sessions on Switch A.

<SwitchA> display bfd session

 Total sessions: 1        Up sessions: 1        Init mode: Active

 

 IPv4 session working in control mode:

 

 LD/RD          SourceAddr      DestAddr        State    Holdtime    Interface

 4/7            12.1.1.1        12.1.1.2        Up       2000ms      Vlan10

The output shows that the BFD session has been created.

# Display the static routes on Switch A.

<SwitchA> display ip routing-table protocol static

 

Summary count : 1

 

Static Routing table status : <Active>

Summary count : 1

 

Destination/Mask    Proto  Pre  Cost         NextHop         Interface

120.1.1.0/24        Static 60   0            12.1.1.2        Vlan10

 

Static Routing table status : <Inactive>

Summary count : 0

The output shows that Switch A communicates with Switch B through VLAN-interface 10. Then the link over VLAN-interface 10 fails.

# Display static routes on Switch A.

<SwitchA> display ip routing-table protocol static

 

Summary count : 1

 

Static Routing table status : <Active>

Summary count : 1

 

Destination/Mask    Proto  Pre  Cost         NextHop         Interface

120.1.1.0/24        Static 65   0            10.1.1.100      Vlan11

 

Static Routing table status : <Inactive>

Summary count : 0

The output shows that Switch A communicates with Switch B through VLAN-interface 11.

Example: Configuring BFD for static routes (indirect next hop)

Network configuration

Figure 4 shows the network topology as follows:

·     Switch A has a route to interface Loopback 1 (2.2.2.9/32) on Switch B, with the output interface VLAN-interface 10.

·     Switch B has a route to interface Loopback 1 (1.1.1.9/32) on Switch A, with the output interface VLAN-interface 12.

·     Switch D has a route to 1.1.1.9/32, with the output interface VLAN-interface 10, and a route to 2.2.2.9/32, with the output interface VLAN-interface 12.

Configure the following:

·     Configure a static route to subnet 120.1.1.0/24 on Switch A.

·     Configure a static route to subnet 121.1.1.0/24 on Switch B.

·     Enable BFD for both routes.

·     Configure a static route to subnet 120.1.1.0/24 and a static route to subnet 121.1.1.0/24 on both Switch C and Switch D.

When the link between Switch A and Switch B through Switch D fails, BFD can detect the failure immediately. Switch A then communicates with Switch B through Switch C.

Figure 4 Network diagram

 

Table 2 Interface and IP address assignment

Device	Interface	IP address
Switch A	VLAN-interface 10	12.1.1.1/24
Switch A	VLAN-interface 11	10.1.1.102/24
Switch A	Loopback 1	1.1.1.9/32
Switch B	VLAN-interface 12	11.1.1.1/24
Switch B	VLAN-interface 13	13.1.1.1/24
Switch B	Loopback 1	2.2.2.9/32
Switch C	VLAN-interface 11	10.1.1.100/24
Switch C	VLAN-interface 13	13.1.1.2/24
Switch D	VLAN-interface 10	12.1.1.2/24
Switch D	VLAN-interface 12	11.1.1.2/24

 

Prerequisites

Configure IP addresses for the interfaces as shown in Figure 4.

Procedure

# Configure static routes on Switch A and enable BFD control packet mode for the static route that traverses Switch D.

<SwitchA> system-view

[SwitchA] bfd multi-hop min-transmit-interval 500

[SwitchA] bfd multi-hop min-receive-interval 500

[SwitchA] bfd multi-hop detect-multiplier 9

[SwitchA] ip route-static 120.1.1.0 24 2.2.2.9 bfd control-packet bfd-source 1.1.1.9

[SwitchA] ip route-static 120.1.1.0 24 vlan-interface 11 10.1.1.100 preference 65

[SwitchA] quit

# Configure static routes on Switch B and enable BFD control packet mode for the static route that traverses Switch D.

<SwitchB> system-view

[SwitchB] bfd multi-hop min-transmit-interval 500

[SwitchB] bfd multi-hop min-receive-interval 500

[SwitchB] bfd multi-hop detect-multiplier 9

[SwitchB] ip route-static 121.1.1.0 24 1.1.1.9 bfd control-packet bfd-source 2.2.2.9

[SwitchB] ip route-static 121.1.1.0 24 vlan-interface 13 13.1.1.2 preference 65

[SwitchB] quit

# Configure static routes on Switch C.

<SwitchC> system-view

[SwitchC] ip route-static 120.1.1.0 24 13.1.1.1

[SwitchC] ip route-static 121.1.1.0 24 10.1.1.102

# Configure static routes on Switch D.

<SwitchD> system-view

[SwitchD] ip route-static 120.1.1.0 24 11.1.1.1

[SwitchD] ip route-static 121.1.1.0 24 12.1.1.1

Verifying the configuration

# Display BFD sessions on Switch A.

<SwitchA> display bfd session

 Total sessions: 1        Up sessions: 1        Init mode: Active

 

 IPv4 session working in control mode:

 

 LD/RD          SourceAddr      DestAddr        State    Holdtime    Interface

 4/7            1.1.1.9         2.2.2.9         Up       2000ms      N/A

The output shows that the BFD session has been created.

# Display the static routes on Switch A.

<SwitchA> display ip routing-table protocol static

 

Summary count : 1

 

Static Routing table status : <Active>

Summary count : 1

 

Destination/Mask    Proto  Pre  Cost         NextHop         Interface

120.1.1.0/24        Static 60   0            12.1.1.2        Vlan10

 

Static Routing table status : <Inactive>

Summary count : 0

The output shows that Switch A communicates with Switch B through VLAN-interface 10. Then the link over VLAN-interface 10 fails.

# Display static routes on Switch A.

<SwitchA> display ip routing-table protocol static

 

Summary count : 1

 

Static Routing table status : <Active>

Summary count : 1

 

Destination/Mask    Proto  Pre  Cost         NextHop         Interface

120.1.1.0/24        Static 65   0            10.1.1.100      Vlan11

 

Static Routing table status : <Inactive>

Summary count : 0

The output shows that Switch A communicates with Switch B through VLAN-interface 11.

Example: Configuring static route FRR

Network configuration

As shown in Figure 5, configure static routes on Switch A, Switch B, and Switch C, and configure static route FRR. When Link A becomes unidirectional, traffic can be switched to Link B immediately.

Figure 5 Network diagram

 

Table 3 Interface and IP address assignment

Device	Interface	IP address
Switch A	VLAN-interface 100	12.12.12.1/24
Switch A	VLAN-interface 200	13.13.13.1/24
Switch A	Loopback 0	1.1.1.1/32
Switch B	VLAN-interface 101	24.24.24.4/24
Switch B	VLAN-interface 200	13.13.13.2/24
Switch B	Loopback 0	4.4.4.4/32
Switch C	VLAN-interface 100	12.12.12.2/24
Switch C	VLAN-interface 101	24.24.24.2/24

 

Prerequisites

Configure IP addresses for the interfaces as shown in Figure 5.

Procedure

1.     Configure static route FRR on link A by using one of the following methods:

¡     (Method 1.) Specify a backup next hop for static route FRR:

# Configure a static route on Switch A, and specify VLAN-interface 100 as the backup output interface and 12.12.12.2 as the backup next hop.

<SwitchA> system-view

[SwitchA] ip route-static 4.4.4.4 32 vlan-interface 200 13.13.13.2 backup-interface vlan-interface 100 backup-nexthop 12.12.12.2

# Configure a static route on Switch B, and specify VLAN-interface 101 as the backup output interface and 24.24.24.2 as the backup next hop.

<SwitchB> system-view

[SwitchB] ip route-static 1.1.1.1 32 vlan-interface 200 13.13.13.1 backup-interface vlan-interface 101 backup-nexthop 24.24.24.2

¡     (Method 2.) Configure static route FRR to automatically select a backup next hop:

# Configure static routes on Switch A, and enable static route FRR.

<SwitchA> system-view

[SwitchA] ip route-static 4.4.4.4 32 vlan-interface 200 13.13.13.2

[SwitchA] ip route-static 4.4.4.4 32 vlan-interface 100 12.12.12.2 preference 70

[SwitchA] ip route-static fast-reroute auto

# Configure static routes on Switch B, and enable static route FRR.

<SwitchB> system-view

[SwitchB] ip route-static 1.1.1.1 32 vlan-interface 200 13.13.13.1

[SwitchB] ip route-static 1.1.1.1 32 vlan-interface 101 24.24.24.2 preference 70

[SwitchB] ip route-static fast-reroute auto

2.     Configure static routes on Switch C.

<SwitchC> system-view

[SwitchC] ip route-static 4.4.4.4 32 vlan-interface 101 24.24.24.4

[SwitchC] ip route-static 1.1.1.1 32 vlan-interface 100 12.12.12.1

Verifying the configuration

# Display route 4.4.4.4/32 on Switch A to view the backup next hop information.

[SwitchA] display ip routing-table 4.4.4.4 verbose

 

Summary count : 1

 

Destination: 4.4.4.4/32

   Protocol: Static          

  Process ID: 0

   SubProtID: 0x0                        Age: 04h20m37s

        Cost: 0                   Preference: 60

       IpPre: N/A                 QosLocalID: N/A

         Tag: 0                        State: Active Adv

   OrigTblID: 0x0                    OrigVrf: default-vrf

     TableID: 0x2                     OrigAs: 0

       NibID: 0x26000002              LastAs: 0

      AttrID: 0xffffffff            Neighbor: 0.0.0.0

       Flags: 0x1008c            OrigNextHop: 13.13.13.2

       Label: NULL               RealNextHop: 13.13.13.2

     BkLabel: NULL                 BkNextHop: 12.12.12.2

     SRLabel: NULL                 Interface: Vlan-interface200

   BkSRLabel: NULL               BkInterface: Vlan-interface100

   Tunnel ID: Invalid            IPInterface: Vlan-interface200

 BkTunnel ID: Invalid          BKIPInterface: Vlan-interface100

     InLabel: NULL            ColorInterface: N/A

    SIDIndex: NULL          BKColorInterface: N/A

    FtnIndex: 0x0            TunnelInterface: N/A

TrafficIndex: N/A          BKTunnelInterface: N/A

   Connector: N/A                     PathID: 0x0

  SRTunnelID: Invalid

    SID Type: N/A                        NID: Invalid

    FlushNID: Invalid                  BkNID: Invalid

  BkFlushNID: Invalid              StatFlags: 0x0

         Exp: N/A

   VpnPeerId: N/A                       Dscp: N/A

         SID: N/A                 OrigLinkID: 0x0

       BkSID: N/A                 RealLinkID: 0x0

CommBlockLen: 0

# Display route 1.1.1.1/32 on Switch B to view the backup next hop information.

[SwitchB] display ip routing-table 1.1.1.1 verbose

 

Summary count : 1

 

Destination: 1.1.1.1/32

   Protocol: Static          

  Process ID: 0

   SubProtID: 0x0                        Age: 04h20m37s

        Cost: 0                   Preference: 60

       IpPre: N/A                 QosLocalID: N/A

         Tag: 0                        State: Active Adv

   OrigTblID: 0x0                    OrigVrf: default-vrf

     TableID: 0x2                     OrigAs: 0

       NibID: 0x26000002              LastAs: 0

      AttrID: 0xffffffff            Neighbor: 0.0.0.0

       Flags: 0x1008c            OrigNextHop: 13.13.13.1

       Label: NULL               RealNextHop: 13.13.13.1

     BkLabel: NULL                 BkNextHop: 24.24.24.2

     SRLabel: NULL                 Interface: Vlan-interface200

   BkSRLabel: NULL               BkInterface: Vlan-interface101

   Tunnel ID: Invalid            IPInterface: Vlan-interface200

 BkTunnel ID: Invalid          BKIPInterface: Vlan-interface101

     InLabel: NULL            ColorInterface: N/A

    SIDIndex: NULL          BKColorInterface: N/A

    FtnIndex: 0x0            TunnelInterface: N/A

TrafficIndex: N/A          BKTunnelInterface: N/A

   Connector: N/A                     PathID: 0x0

  SRTunnelID: Invalid

    SID Type: N/A                        NID: Invalid

    FlushNID: Invalid                  BkNID: Invalid

  BkFlushNID: Invalid              StatFlags: 0x0

         Exp: N/A

   VpnPeerId: N/A                       Dscp: N/A

         SID: N/A                 OrigLinkID: 0x0

       BkSID: N/A                 RealLinkID: 0x0

CommBlockLen: 0

Configuring a default route

A default route is used to forward packets that do not match any specific routing entry in the routing table. Without a default route, packets that do not match any routing entries are discarded and an ICMP destination-unreachable packet is sent to the source.

A default route can be configured in either of the following ways:

·     The network administrator can configure a default route with both destination and mask being 0.0.0.0. For more information, see "Configuring static routing."

·     Some dynamic routing protocols can generate a default route. For example, an upstream router running OSPF can generate a default route and advertise it to other routers. These routers install the default route with the next hop being the upstream router. For more information, see the respective chapters on these routing protocols in this configuration guide.