IP Routing Features
Configuring Static IP Routes
■Default network route – This is a specific static route that the routing switch uses if other routes to the destination are not available. Refer to “Configuring the Default Route” in the chapter titled “IP Routing Features” in the Management and Configuration Guide for your switch.
Static Route Types
You can configure the following types of static IP routes:
■Standard – the static route consists of the destination network address and network mask, and the IP address of the
■Null (reject) – the static route consists of the destination network address and network mask, and the reject parameter. 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 “loop back” network, with the single exception of traffic to the host address of the switch’s loopback interface (127.0.0.1/32). Figure Figure
Static IP Route Parameters
When you configure a static IP route, you must specify the following param eters:
■The IP address and network mask for the route’s destination network.
■The route’s path, which can be one of the following:
•The IP address of a
•A “null” interface. In this case the routing switch invokes a “reject” parameter on a static route entry, which results in the switch dropping traffic forwarded to the null interface.
The switch automatically assigns a metric of “1” to an IP static route.
Static Route States Follow VLAN (Interface) States
IP static routes remain in the IP route table only so long as the VLAN interface used by the route is available. If the VLAN becomes unavailable (that is, if all ports in the VLAN are offline), the software removes the static route from the IP route table. If the VLAN later becomes available again, the software adds the route back to the route table.