Dell FCX624-I Laptop User Manual


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PowerConnect B-Series FCX Configuration Guide 823
53-1002266-01
Configuring IP parameters – Layer 3 Switches
26
If you do not want to specify a next-hop IP address, you can instead specify a port or interface
number on the Layer 3 Switch. The <num> parameter is a virtual interface number. If you instead
specify an Ethernet port, the <portnum> is the port number (including the slot number, if you are
configuring a Chassis device). In this case, the Layer 3 Switch forwards packets destined for the
static route destination network to the specified interface. Conceptually, this feature makes the
destination network like a directly connected network, associated with a specific Layer 3 Switch
interface.
NOTE
The port or virtual interface you use for the static route next hop must have at least one IP address
configured on it. The address does not need to be in the same subnet as the destination network.
The <metric> parameter can be a number from 1 through 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.
The distance <num> parameter specifies the administrative distance of the route. 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.
NOTE
The Layer 3 Switch will replace the static route if the it receives a route with a lower administrative
distance. Refer to “Changing administrative distances” on page 1014 for a list of the default
administrative distances for all types of routes.
NOTE
You can also assign the default router as the destination by entering 0.0.0.0 0.0.0.0 xxx.xxx.xxx.xxx.
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.
To configure a null static route to drop packets destined for network 209.157.22.x, enter the
following commands.
PowerConnect(config)# ip route 209.157.22.0 255.255.255.0 null0
PowerConnect(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.