Static route types
You can configure the following types of static IP routes:
- Standard
The static route consists of a destination network address or host, a corresponding network mask, and the IP address of the next-hop IP address.
- Null (discard)
The null route consists of the destination network address or host, a corresponding network mask, and either the
reject
orblackhole
keyword. Typically, the null route is configured as a backup route for discarding traffic if the primary route is unavailable. By default, when IP routing is enabled, a route for the 127.0.0.0/8 network is created to the null interface. Traffic to this interface is rejected (dropped.)
This route is for all traffic to the "loopback" network, with the single exception of traffic to the host address of the switch's loopback interface (127.0.0.1/32.) Figure A-3 on page 1-6 shows the default null route entry in the switch's routing table.
On a single routing switch you can create one null route to a given destination. Multiple null routes to the same destination are not supported.