Configuring static routing· 1

Configuring a static route· 1

Configuring BFD for static routes 2

BFD control mode· 2

BFD echo mode· 3

Configuring static route FRR· 4

Configuration prerequisites 4

Configuration guidelines 4

Configuration procedure· 5

Displaying and maintaining static routes 5

Static route configuration examples 5

Basic static route configuration example· 5

BFD for static routes configuration example (direct next hop) 7

BFD for static routes configuration example (indirect next hop) 10

Static route FRR configuration example· 12

Configuring a default route· 1

 

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

Before you configure a static route, complete the following tasks:

·     Configure the physical parameters for related interfaces.

·     Configure the link-layer attributes for related interfaces.

·     Configure the IP addresses for related interfaces.

Follow these guidelines when you configure a static route:

·     The next hop address of a static route cannot be the IP address of a local interface. Otherwise, the static route does not take effect.

·     You can associate track entry with a static route to monitor the reachability of the next hops. For more information about Track, see High Availability Configuration Guide.

To configure a static route:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Configure a static route.	·     Method 1: ip route-static dest-address { mask | mask-length } { next-hop-address [ track track-entry-number ] | interface-type interface-number [ next-hop-address ] | vpn-instance d-vpn-instance-name next-hop-address [ track track-entry-number ] } [ preference preference-value ] [ tag tag-value ] [ permanent ] [ description description-text ] ·     Method 2: ip route-static vpn-instance s-vpn-instance-name&<1-6> dest-address { mask | mask-length } { next-hop-address [ public ] [ track track-entry-number ] | interface-type interface-number [ next-hop-address ] | vpn-instance d-vpn-instance-name next-hop-address track track-entry-number } [ preference preference-value ] [ tag tag-value ] [ permanent ] [ description description-text ]	Use either method. By default, no static route is configured.
3.     Configure the default preference for static routes.	ip route-static default-preference default-preference-value	Optional. 60 by default.
4.     Delete all static routes, including the default route.	delete [ vpn-instance vpn-instance-name ] static-routes all	Optional. To delete one static route, use the undo ip route-static command.

 

Configuring BFD for static routes

Bidirectional forwarding detection (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 and Multiprotocol Label Switching (MPLS). For more information about BFD, see High Availability Configuration Guide.

BFD control mode

To use BFD bidirectional control detection between two devices, enable BFD control mode for each device's static route destined to the peer.

To configure a static route and enable BFD control mode for it, specify an output interface and a direct next hop, or specify an indirect next hop and a specific BFD packet source address for the static route.

To configure BFD control mode for a static route (direct next hop):

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Configure BFD control mode for a static route.	·     Method 1: ip route-static dest-address { mask | mask-length } interface-type interface-number next-hop-address bfd control-packet [ preference preference-value ] [ tag tag-value ] [ description description-text ] ·     Method 2: ip route-static vpn-instance s-vpn-instance-name&<1-6> dest-address { mask | mask-length } interface-type interface-number next-hop-address bfd control-packet [ preference preference-value ] [ tag tag-value ] [ description description-text ]	Use either method.

 

To configure BFD control mode for a static route (indirect next hop):

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Configure BFD control mode for a static route.	·     Method 1: ip route-static dest-address { mask | mask-length } { 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-value ] [ tag tag-value ] [ description description-text ] ·     Method 2: ip route-static vpn-instance s-vpn-instance-name&<1-6> { dest-address { mask | mask-length } 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-value ] [ tag tag-value ] [ description description-text ]	Use either method.

 

BFD echo mode

With BFD echo mode enabled for a static route, the local switch sends BFD echo packets to the peer, which loops it back to test the link.

Follow these guidelines when you configure BFD echo mode for static routes:

·     Enabling BFD for a flapping route could worsen the situation.

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

·     BFD can be used for static routes with direct next hops rather than indirect next hops.

·     A BFD session is established at only one end when the echo mode is used.

·     For the echo and control mode, the switch does not support BFD detection on tunnel interfaces.

To configure BFD echo mode for static routes:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Configure the source address of echo packets.	bfd echo-source-ip ip-address	Not configured by default. For more information about this command, see High Availability Command Reference.
3.     Enable BFD echo mode for static routes.	·     Method 1: ip route-static dest-address { mask | mask-length } interface-type interface-number next-hop-address bfd echo-packet [ preference preference-value ] [ tag tag-value ] [ description description-text ] ·     Method 2: ip route-static vpn-instance s-vpn-instance-name&<1-6> dest-address { mask | mask-length } interface-type interface-number next-hop-address bfd echo-packet [ preference preference-value ] [ tag tag-value ] [ description description-text ]	Use either method.

 

Configuring static route FRR

A link or router failure on a path can cause packet loss and even routing loop. 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, FRR designates a backup next hop by using a routing policy for routes matching the specified criteria. Packets are directed to the backup next hop to avoid traffic interruption.

Configuration prerequisites

Create a routing policy to be referenced by FRR and use the apply fast-reroute backup-interface command to specify a backup next hop in a routing policy. For more information about the command and routing policy configurations, see "Configuring routing policies."

Configuration guidelines

·     Static route FRR takes effect only for static routes that have both the output interface and next hop specified.

·     Do not use FRR and BFD at the same time.

Configuration procedure

To configure static route FRR:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
1.     Configure the source address of BFD echo packets.	bfd echo-source-ip ip-address	Not configured by default. For more information about this command, see High Availability Command Reference.
2.     Configure static route FRR.	ip route-static [ vpn-instance vpn-instance-name ] fast-reroute route-policy route-policy-name	Not configured by default.

 

Displaying and maintaining static routes

Task	Command	Remarks
Display static route information.	display ip routing-table protocol static [ inactive | verbose ] [ | { begin | exclude | include } regular-expression ]	Available in any view.
Delete all static routes.	delete [ vpn-instance vpn-instance-name ] static-routes all	Available in system view.

 

Static route configuration examples

By default, Ethernet, VLAN, and aggregate interfaces are down. Before configuring these interfaces, bring them up by using the undo shutdown command.

Basic static route configuration example

Network requirements

Configure static routes in Figure 2 for interconnections between any two hosts.

Figure 2 Network diagram

 

Configuration procedure

1.     Configure IP addresses for interfaces. (Details not shown.)

2.     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

3.     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.)

4.     Verify the configuration:

# Display the IP routing table on Switch A.

[SwitchA] display ip routing-table

Routing Tables: Public

         Destinations : 7       Routes : 7

 

Destination/Mask    Proto  Pre  Cost         NextHop         Interface

 

0.0.0.0/0           Static 60   0            1.1.4.2         Vlan500

1.1.2.0/24          Direct 0    0            1.1.2.3         Vlan300

1.1.2.3/32          Direct 0    0            127.0.0.1       InLoop0

1.1.4.0/30          Direct 0    0            1.1.4.1         Vlan500

1.1.4.1/32          Direct 0    0            127.0.0.1       InLoop0

127.0.0.0/8         Direct 0    0            127.0.0.1       InLoop0

127.0.0.1/32        Direct 0    0            127.0.0.1       InLoop0

# Display the IP routing table on Switch B.

[SwitchB] display ip routing-table

Routing Tables: Public

         Destinations : 10       Routes : 10

 

Destination/Mask    Proto  Pre  Cost         NextHop         Interface

 

1.1.2.0/24          Static 60   0            1.1.4.1         Vlan500

1.1.3.0/24          Static 60   0            1.1.5.6         Vlan600

1.1.4.0/30          Direct 0    0            1.1.4.2         Vlan500

1.1.4.2/32          Direct 0    0            127.0.0.1       InLoop0

1.1.5.0/30          Direct 0    0            1.1.5.5         Vlan600

1.1.5.5/32          Direct 0    0            127.0.0.1       InLoop0

127.0.0.0/8         Direct 0    0            127.0.0.1       InLoop0

127.0.0.1/32        Direct 0    0            127.0.0.1       InLoop0

1.1.6.0/24          Direct 0    0            1.1.6.1         Vlan100

1.1.6.1/32          Direct 0    0            127.0.0.1       InLoop0

# Use the ping command on Host B to test reachability to 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 reachability to 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.

BFD for static routes configuration example (direct next hop)

Network requirements

As shown in Figure 3, configure a static route to subnet 120.1.1.0/24 on Switch A and configure a static route to subnet 121.1.1.0/24 on Switch B. Enable BFD for both routes so that when the link between Switch A and Switch B through the Layer 2 switch fails, BFD can detect the failure immediately and Switch A and Switch B can communicate through Switch C.

Figure 3 Network diagram

Device	Interface	IP address	Device	Interface	IP address
Switch A	Vlan-int10	12.1.1.1/24	Switch B	Vlan-int10	12.1.1.2/24
	Vlan-int11	10.1.1.102/24		Vlan-int13	13.1.1.1/24
Switch C	Vlan-int11	10.1.1.100/24
	Vlan-int13	13.1.1.2/24

 

Configuration procedure

1.     Configure IP addresses for the interfaces. (Details not shown.)

2.     Configure static routes and BFD:

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

<SwitchA> system-view

[SwitchA] interface vlan-interface10

[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 mode for the static route that traverses the Layer 2 switch.

<SwitchB> system-view

[SwitchB] interface vlan-interface10

[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

3.     Verify the configuration:

# Display BFD sessions on Switch A.

<SwitchA> display bfd session

 

 Total Session Num: 1            Init Mode: Active

 

 Session Working Under Ctrl Mode:

 

 LD/RD         SourceAddr      DestAddr        State Holdtime Interface

 4/7           12.1.1.1        12.1.1.2        Up    2000ms   Vlan10

# Display static routes on Switch A.

<SwitchA> display ip routing-table protocol static

Public Routing Table : Static

Summary Count : 2

 

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

 

Direct Routing table Status : <Inactive>

Summary Count : 1

Destination/Mask    Proto  Pre  Cost         NextHop         Interface

120.1.1.0/24        Static 65   0            10.1.1.100      Vlan11

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

# Enable BFD debugging.

<SwitchA> debugging bfd event

<SwitchA> debugging bfd scm

<SwitchA> terminal debugging

%Jul 27 10:18:18:672 2007 SwitchA BFD/4/LOG:Sess[12.1.1.1/12.1.1.2, Vlan10,Ctrl], Sta: UP->DOWN, Diag: 1

*Jul 27 10:18:18:672 2007 SwitchA BFD/7/EVENT:Send sess-down Msg, [Src:12.1.1.1,Dst:12.1.1.2, Vlan10,Ctrl], instance:0, protocol:STATIC

*Jul 27 10:18:19:172 2007 SwitchA BFD/7/EVENT:Receive Delete-sess, [Src:12.1.1.1,Dst:12.1.1.2, Vlan10,Ctrl], Direct, Instance:0x0, Proto:STATIC

*Jul 27 10:18:19:172 2007 SwitchA BFD/7/EVENT:Notify driver to stop receiving bf

The output shows that Switch A can quickly detect the failure.

# Display static routes on Switch A again.

<SwitchA> display ip routing-table protocol static

Public Routing Table : Static

Summary Count : 2

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 : 1

Destination/Mask    Proto  Pre  Cost         NextHop         Interface

120.1.1.0/24        Static 60   0            12.1.1.2        Vlan10

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

BFD for static routes configuration example (indirect next hop)

Network requirements

As shown in Figure 4, Switch A has a route to interface Loopback 1 (2.2.2.9/32) on Switch B, with output interface VLAN-interface 10. Switch B has a route to interface Loopback 1 (1.1.1.9/32) on Switch A, with output interface VLAN-interface 12. Switch D has a route to 1.1.1.9/32, with output interface VLAN-interface 10, and a route to 2.2.2.9/32, with output interface VLAN-interface 12.

Configure a static route to subnet 120.1.1.0/24 on Switch A and configure a static route to subnet 121.1.1.0/24 on Switch B. Enable BFD for both routes so that when the link between Switch A and Switch B through Switch D fails, BFD can detect the failure immediately and Switch A and Switch B can communicate through Switch C.

Figure 4 Network diagram

Device	Interface	IP address	Device	Interface	IP address
Switch A	Vlan-int10	12.1.1.1/24	Switch B	Vlan-int12	11.1.1.1/24
	Vlan-int11	10.1.1.102/24		Vlan-int13	13.1.1.1/24
	Loop1	1.1.1.9/32		Loop1	2.2.2.9/32
Switch C	Vlan-int11	10.1.1.100/24	Switch D	Vlan-int10	12.1.1.2/24
	Vlan-int13	13.1.1.2/24		Vlan-int12	11.1.1.2/24

 

Configuration procedure

1.     Configure IP addresses for the interfaces. (Details not shown.)

2.     Configure static routes and BFD:

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

<SwitchA> system-view

[SwitchA] interface loopback 1

[SwitchA-LoopBack1] bfd min-transmit-interval 500

[SwitchA-LoopBack1] bfd min-receive-interval 500

[SwitchA-LoopBack1] bfd detect-multiplier 9

[SwitchA-LoopBack1] quit

[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 mode for the static route that traverses Switch D.

<SwitchB> system-view

[SwitchB] interface loopback 1

[SwitchB-LoopBack1] bfd min-transmit-interval 500

[SwitchB-LoopBack1] bfd min-receive-interval 500

[SwitchB-LoopBack1] bfd detect-multiplier 9

[SwitchB-LoopBack1] quit

[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

3.     Verify the configuration:

# Display BFD sessions on Switch A.

<SwitchA> display bfd session

 

Total session number: 1   Up session number: 0   Init mode: Active

 

 IPv4 session working under Ctrl mode:

 

 LD/RD         SourceAddr      DestAddr        State Holdtime Interface

 4/7           1.1.1.9         2.2.2.9         Up    2000ms   Loop1

# Display static routes on Switch A.

<SwitchA> display ip routing-table protocol static

Public Routing Table : Static

Summary Count : 2

 

Static Routing table Status : <Active>

Summary Count : 1

Destination/Mask    Proto  Pre  Cost         NextHop         Interface

120.1.1.0/24        Static 60   0            2.2.2.9         Vlan10

 

Static Routing table Status : <Inactive>

Summary Count : 1

Destination/Mask    Proto  Pre  Cost         NextHop         Interface

120.1.1.0/24        Static 65   0            10.1.1.100      Vlan11

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

# Enable BFD debugging.

<SwitchA> debugging bfd event

<SwitchA> debugging bfd scm

<SwitchA> terminal debugging

%Oct 10 10:18:18:672 2010 SwitchA BFD/4/LOG:Sess[1.1.1.9/2.2.2.9, Loop1,Ctrl], Sta: UP->DOWN, Diag: 1

* Oct 10 10:18:18:672 2010 SwitchA BFD/7/EVENT:Send sess-down Msg, [Src:1.1.1.9,Dst:2.2.2.9, Loop1,Ctrl], instance:0, protocol:STATIC

The output shows that Switch A can quickly detect the failure.

# Display static routes on Switch A again.

<SwitchA> display ip routing-table protocol static

Public Routing Table : Static

Summary Count : 2

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 : 1

Destination/Mask    Proto  Pre  Cost         NextHop         Interface

120.1.1.0/24        Static 60   0            2.2.2.9

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

Static route FRR configuration example

Network requirements

Figure 5 shows that Switch S, Switch A, and Switch D are interconnected through static routes. Configure static route FRR so that when Link A between Switch S and Switch D fails, traffic can be switched to Link B immediately.

Figure 5 Network diagram

 

Configuration procedure

1.     Configure IP addresses for the interfaces. (Details not shown.)

2.     Configure static routes:

Configure static routes on Switch S, Switch A, and Switch D so that Switch S can reach Loopback 0 on Switch D and Switch D can reach Loopback 0 on Switch S.

# Configure a static route on Switch S.

<SwitchS> system-view

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

# Configure a static route on Switch D.

<SwitchD> system-view

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

# Configure a static route on Switch A.

<SwitchA> system-view

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

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

3.     Configure static route FRR:

# Configure Switch S.

[SwitchS] bfd echo-source-ip 1.1.1.1

[SwitchS] ip ip-prefix abc index 10 permit 4.4.4.4 32

[SwitchS] route-policy frr permit node 10

[SwitchS-route-policy] if-match ip-prefix abc

[SwitchS-route-policy] apply fast-reroute backup-interface vlan-interface 100 backup-nexthop 12.12.12.2

[SwitchS-route-policy] quit

[SwitchS] ip route-static fast-reroute route-policy frr

# Configure Switch D.

[SwitchD] bfd echo-source-ip 4.4.4.4

[SwitchD] ip ip-prefix abc index 10 permit 1.1.1.1 32

[SwitchD] route-policy frr permit node 10

[SwitchD-route-policy] if-match ip-prefix abc

[SwitchD-route-policy] apply fast-reroute backup-interface vlan-interface 101 backup-nexthop 24.24.24.2

[SwitchD-route-policy] quit

[SwitchD] ip route-static fast-reroute route-policy frr

4.     Verify the configuration:

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

[SwitchS] display ip routing-table 4.4.4.4 verbose

Routing Table : Public

Summary Count : 2

  Destination: 4.4.4.4/32

     Protocol: Static          Process ID: 0

   Preference: 60                    Cost: 0

 IpPrecedence:                    QosLcID:

      NextHop: 13.13.13.2       Interface: vlan 200

    BkNextHop: 12.12.12.2     BkInterface: vlan 100

  RelyNextHop: 0.0.0.0          Neighbor : 0.0.0.0

    Tunnel ID: 0x0                  Label: NULL

  BKTunnel ID: 0x0                BKLabel: NULL

        State: Active Adv             Age: 00h01m27s

          Tag: 0

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

[SwitchD] display ip routing-table 1.1.1.1 verbose

Routing Table : Public

Summary Count : 2

  Destination: 1.1.1.1/32

     Protocol: Static          Process ID: 0

   Preference: 60                    Cost: 0

 IpPrecedence:                    QosLcID:

      NextHop: 13.13.13.1       Interface: vlan 200

    BkNextHop: 24.24.24.2     BkInterface: vlan 101

  RelyNextHop: 0.0.0.0          Neighbor : 0.0.0.0

    Tunnel ID: 0x0                  Label: NULL

  BKTunnel ID: 0x0                BKLabel: NULL

        State: Active Adv             Age: 00h01m27s

          Tag: 0

A default route is used to forward packets that match no entry in the routing table.

Without a default route, a packet that does not match any routing entries is 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 a static route.

·     Some dynamic routing protocols, such as OSPF, RIP, and IS-IS, can generate a default route. For example, an upstream router running OSPF can generate a default route and advertise it to other routers, which install the default route with the next hop being the upstream router. For more information, see configuration guides of relevant routing protocols.