Configuring Rarp - Foundry Networks FESX Manual

Enabling IRDP Globally
To globally enable IRDP, enter the following command:
FastIron SuperX Router(config)# ip irdp
This command enables IRDP on the IP interfaces on all ports. Each port uses the default values for the IRDP
parameters. The parameters are not configurable when IRDP is globally enabled.
Enabling IRDP on an Individual Port
To enable IRDP on an individual interface and change IRDP parameters, enter commands such as the following:
FastIron SuperX Router(config)# interface ethernet 1/3
FastIron SuperX Router(config-if-1/3)# ip irdp maxadvertinterval 400
This example shows how to enable IRDP on a specific port and change the maximum advertisement interval for
Router Advertisement messages to 400 seconds.
NOTE: To enable IRDP on individual ports, you must leave the feature globally disabled.
Syntax: [no] ip irdp [broadcast | multicast] [holdtime <seconds>] [maxadvertinterval <seconds>]
[minadvertinterval <seconds>] [preference <number>]
The broadcast | multicast parameter specifies the packet type the Layer 3 Switch uses to send Router
Advertisement.
• broadcast – The Layer 3 Switch sends Router Advertisement as IP broadcasts. This is the default.
• multicast – The Layer 3 Switch sends Router Advertisement as multicast packets addressed to IP multicast
group 224.0.0.1.
The holdtime <seconds> parameter specifies how long a host that receives a Router Advertisement from the
Layer 3 Switch should consider the advertisement to be valid. When a host receives a new Router Advertisement
message from the Layer 3 Switch, the host resets the hold time for the Layer 3 Switch to the hold time specified in
the new advertisement. If the hold time of an advertisement expires, the host discards the advertisement,
concluding that the router interface that sent the advertisement is no longer available. The value must be greater
than the value of the maxadvertinterval parameter and cannot be greater than 9000. The default is three times
the value of the maxadvertinterval parameter.
The maxadvertinterval parameter specifies the maximum amount of time the Layer 3 Switch waits between
sending Router Advertisements. You can specify a value from 1 to the current value of the holdtime parameter.
The default is 600 seconds.
The minadvertinterval parameter specifies the minimum amount of time the Layer 3 Switch can wait between
sending Router Advertisements. The default is three-fourths (0.75) the value of the maxadvertinterval
parameter. If you change the maxadvertinterval parameter, the software automatically adjusts the
minadvertinterval parameter to be three-fourths the new value of the maxadvertinterval parameter. If you want
to override the automatically configured value, you can specify an interval from 1 to the current value of the
maxadvertinterval parameter.
The preference <number> parameter specifies the IRDP preference level of this Layer 3 Switch. If a host
receives Router Advertisements from multiple routers, the host selects the router interface that sent the message
with the highest interval as the host's default gateway. The valid range is -4294967296 to 4294967295. The
default is 0.

Configuring RARP

The Reverse Address Resolution Protocol (RARP) provides a simple mechanism for directly-attached IP hosts to
boot over the network. RARP allows an IP host that does not have a means of storing its IP address across power
cycles or software reloads to query a directly-attached router for an IP address.
RARP is enabled by default. However, you must create a RARP entry for each host that will use the Layer 3
Switch for booting. A RARP entry consists of the following information:
• The entry number – the entry's sequence number in the RARP table.
December 2005 © Foundry Networks, Inc.
Configuring IP
16 - 45