Foundry Networks Switch and Router Installation And Configuration Manual page 485

• If you are modifying an existing static route, click on the Modify button to the right of the row describing
the static route to display the Static Route configuration panel.
6. Enter the network address for the route in the Network field.
7. Enter the network mask in the Mask field.
8. Select the next-hop type. You can select one of the following:
• Address – The next-hop is the IP address of a gateway router.
• Interface – The next hop is a port, loopback interface, or virtual interface on the Layer 3 Switch.
9. Enter the next-hop IP address (if you selected the Address method) or select the interface (if you selected the
Interface method).
• Address – Enter the IP address of the next-hop gateway in the Next Hop (by Address) field.
• Interface – Select the port, loopback interface, or virtual interface from the Next Hop (by Interface) field's
pulldown menu(s). Loopback interfaces and virtual interfaces are listed in the Port pulldown menu, not in
the Slot pulldown menu. To select a loopback interface or a virtual interface on a Chassis device, ignore
the Slot pulldown menu and select the interface from the Port pulldown menu.
10. Optionally change the metric by editing the value in the Metric field. You can specify a number from 1 – 16.
The default is 1.
NOTE: If you specify 16, RIP considers the metric to be infinite and thus also considers the route to be
unreachable.
11. Optionally change the administrative distance by editing the value in the Distance field. When comparing
otherwise equal routes to a destination, the Layer 3 Switch prefers lower administrative distances over higher
ones, so make sure you use a low value for your default route. The default is 1.
12. Click the Add button to save the change to the device's running-config file.
13. Repeat steps 8 – 12 for each static route to the same destination.
14. Select the Save link at the bottom of the dialog. Select Yes when prompted to save the configuration change
to the startup-config file on the device's flash memory.
Configuring a "Null" Route
You can configure the Layer 3 Switch to drop IP packets to a specific network or host address by configuring a
"null" (sometimes called "null0") static route for the address. When the Layer 3 Switch receives a packet destined
for the address, the Layer 3 Switch drops the packet instead of forwarding it.
To configure a null static route, use the following CLI method.
USING THE CLI
To configure a null static route to drop packets destined for network 209.157.22.x, enter the following commands.
BigIron(config)# ip route 209.157.22.0 255.255.255.0 null0
BigIron(config)# write memory
Syntax: ip route <ip-addr> <ip-mask> null0 [<metric>] [distance <num>]
or
Syntax: ip route <ip-addr>/<mask-bits> null0 [<metric>] [distance <num>]
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-max ip-static-route <num> command at the global
CONFIG level.
The <ip-addr> parameter specifies the network or host address. The Layer 3 Switch will drop packets that contain
this address in the destination field instead of forwarding them.
December 2000
Configuring IP
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