Creating IPv4 Static Routes

When creating an IPv4 static route, you need the following information:

• Destination address and mask

  In the ip route-static command, the IPv4 address is expressed in dotted decimal notation, and the mask is expressed either in dotted decimal notation or represented by the mask length.

• Outbound interface and next hop address

  When creating a static route, you can specify an outbound interface, a next hop address, or both of them, depending on actual requirements.

  Actually, each routing entry requires a next hop address. Before sending a packet, a device needs to search its routing table for the route matching the destination address in the packet based on the longest match rule. The device can find the associated link layer address to forward the packet only when the next hop address of the packet is available.

  When specifying an outbound interface, note the following rules:

  • For a Point-to-Point (P2P) interface, if the outbound interface is specified, the next hop address is the address of the remote interface connected to the outbound interface.

  • Non-Broadcast Multiple-Access (NBMA) interfaces are applicable to Point-to-Multipoint networks. Therefore, you need to configure IP routes and the mappings between IP addresses and link layer addresses. In this case, next hop addresses need to be configured.

  • An Ethernet interface is a broadcast interface and a virtual-template (VT) interface can be associated with multiple virtual access interfaces. If the Ethernet interface or the VT interface is specified as the outbound interface of a static route, the next hop cannot be determined because multiple next hops exist. Therefore, do not specify an Ethernet interface or a VT interface as the outbound interface unless necessary. If you need to specify a broadcast interface (such as an Ethernet interface), a VT interface, or an NBMA interface as the outbound interface, you are recommended to specify the associated next hop address at the same time.

• Other attributes

  You can configure different priorities for different static routes so that routing management policies can be flexibly applied. For example, when creating multiple routes to the same destination address, you can set the same priority for these routes to implement load balancing. You can also set different priorities to implement routing redundancy.

  By configuring different tag values, you can classify static routes to implement different routing policies. For example, other protocols can import static routes with specified tag values based on routing policies.

  If service traffic needs to be forwarded along a specified path, regardless of the link status, you can configure permanent advertisement of static routes by using permanent.

  In network maintenance scenarios, static routes are required to verify services. If you do not want these static routes to be imported by other protocols, specify no-advertise to prevent these static routes from being advertised.

  If you set the destination address and the mask to all 0s (0.0.0.0 0.0.0.0) in the ip route-static command, a default route is configured.