IP Routing Features

Overview of IP Routing

Each IP route table entry contains the destination’s IP address and sub-net mask and the IP address of the next-hop router interface to the destination. Each entry also indicates route type, and for OSPF routes, the sub type, and the route’s IP metric (cost). The type indicates how the IP route table received the route.

To configure a static IP route, see “Configuring a Static IP Route” on page 16-18

IP Forwarding Cache

The IP forwarding cache provides a fast-path mechanism for forwarding IP packets. The cache contains entries for IP destinations. When an HP ProCurve routing switch has completed processing and addressing for a packet and is ready to forward the packet, the device checks the IP forwarding cache for an entry to the packet’s destination.

If the cache contains an entry with the destination IP address, the device uses the information in the entry to forward the packet out the ports listed in the entry. The destination IP address is the address of the packet’s final destination. The port numbers are the ports through which the destination can be reached.

If the cache does not contain an entry, the software can create an entry in the forwarding cache.

 

Each entry in the IP forwarding cache has an age timer. If the entry remains

 

unused for five minutes, the software removes the entry. The age timer is not

 

configurable.

 

 

N o t e

You cannot add static entries to the IP forwarding cache.

 

 

16-5