Overview of IPv4 Static Routing
Static routes can be used to specify
desired routes, backup routes, or routes of last resort. Static routing can help provide
load balancing and can use routing information learned from other protocols.
The IPv4 route table can receive routes from
several sources, such as static routes, directly connected networks, OSPF, BGP4, and
ISIS protocols.
Static routes are manually configured entries in
the IPv4 routing table. In setting up static routes, you can specify several types of
destinations:
- Destination network, using an IP
address and prefix length
- Default network route
- Next-hop router
- Ethernet interface, typically used for
directly attached destination networks
- Port-channel interface
- Virtual interface
- Null interface
You can influence the preference a route is
given:
- Configure a route metric higher than
the default metric
- Give the route an administrative
distance
- Specify a route tag for use with a
route map.
Static routes can be configured to serve as any of the following:
- Default routes
- Primary routes
- Backup routes
- Null routes for intentionally dropping traffic when the desired connection fails
- Alternative routes to the same destination to help
load balance traffic
