Configuring IP

To display the maximum value for your device, enter the show default values command. The maximum number of static IP routes the system can hold is listed in the ip-static-route row in the System Parameters section of the display. To change the maximum value, use the system-maxip-static-route<num> command at the global CONFIG level.

The <ip-addr> parameter specifies the network or host address. The routing switch will drop packets that contain this address in the destination field instead of forwarding them.

The <ip-mask> parameter specifies the network mask. Ones are significant bits and zeros allow any value. For example, the mask 255.255.255.0 matches on all hosts within the Class C sub-net address specified by <ip-addr>. Alternatively, you can specify the number of bits in the network mask. For example, you can enter 209.157.22.0/ 24 instead of 209.157.22.0 255.255.255.0.

The null0 parameter indicates that this is a null route. You must specify this parameter to make this a null route.

The <metric> parameter adds a cost to the route. You can specify from 1 – 16. The default is 1.

The distance <num> parameter configures the administrative distance for the route. You can specify a value from 1 – 255. The default is 1. The value 255 makes the route unusable.

NOTE: The last two parameters are optional and do not affect the null route, unless you configure the administrative distance to be 255. In this case, the route is not used and the traffic might be forwarded instead of dropped.

USING THE WEB MANAGEMENT INTERFACE

You cannot configure a null IP static route using the Web management interface.

Configuring Load Balancing and Redundancy Using Multiple Static Routes to the Same Destination

You can configure multiple static IP routes to the same destination, for the following benefits:

•IP load sharing – If you configure more than one static route to the same destination, and the routes have different next-hop gateways but have the same metrics, the routing switch load balances among the routes using basic round-robin. For example, if you configure two static routes with the same metrics but to different gateways, the routing switch alternates between the two routes. For information about IP load balancing, see “Configuring IP Load Sharing” on page 6-48.

•Backup Routes – If you configure multiple static IP routes to the same destination, but give the routes different next-hop gateways and different metrics, the routing switch will always use the route with the lowest metric. If this route becomes unavailable, the routing switch will fail over to the static route with the next-lowest metric, and so on.

NOTE: You also can bias the routing switch to select one of the routes by configuring them with different administrative distances. However, make sure you do not give a static route a higher administrative distance than other types of routes, unless you want those other types to be preferred over the static route. For a list of the default administrative distances, see “Changing Administrative Distances” on page 10-30.

The steps for configuring the static routes are the same as described in the previous section. The following sections provide examples.

USING THE CLI

To configure multiple static IP routes, enter commands such as the following.

HP9300(config)# ip route 192.128.2.69 255.255.255.0 209.157.22.1 HP9300(config)# ip route 192.128.2.69 255.255.255.0 192.111.10.1

The commands in the example above configure two static IP routes. The routes go to different next-hop gateways but have the same metrics. These commands use the default metric value (1), so the metric is not specified. These static routes are used for load sharing among the next-hop gateways.

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