Configuring IP
NOTE: You can configure IRDP parameters only an individual port basis. To do so, IRDP must be disabled globally and enabled only on individual ports. You cannot configure IRDP parameters if the feature is globally enabled.
When IRDP is enabled, the routing switch periodically sends Router Advertisement messages out the IP interfaces on which the feature is enabled. The messages advertise the routing switch’s IP addresses to directly attached hosts who listen for the messages. In addition, hosts can be configured to query the routing switch for the information by sending Router Solicitation messages.
Some types of hosts use the Router Solicitation messages to discover their default gateway. When IRDP is enabled on the HP routing switch, the routing switch responds to the Router Solicitation messages. Some clients interpret this response to mean that the routing switch is the default gateway. If another router is actually the default gateway for these clients, leave IRDP disabled on the HP routing switch.
IRDP uses the following parameters. If you enable IRDP on individual ports instead of enabling the feature globally, you can configure these parameters on an individual port basis.
•Packet type – The routing switch can send Router Advertisement messages as IP broadcasts or as IP multicasts addressed to IP multicast group 224.0.0.1. The packet type is IP broadcast.
•Maximum message interval and minimum message interval – When IRDP is enabled, the routing switch sends the Router Advertisement messages every 450 – 600 seconds by default. The time within this interval that the routing switch selects is random for each message and is not affected by traffic loads or other network factors. The random interval minimizes the probability that a host will receive Router Advertisement messages from other routers at the same time. The interval on each
•Hold time – Each Router Advertisement message contains a hold time value. This value specifies the maximum amount of time the host should consider an advertisement to be valid until a newer advertisement arrives. When a new advertisement arrives, the hold time is reset. The hold time is always longer than the maximum advertisement interval. Therefore, if the hold time for an advertisement expires, the host can reasonably conclude that the router interface that sent the advertisement is no longer available. The default hold time is three times the maximum message interval.
•Preference – If a host receives multiple Router Advertisement messages from different routers, the host selects the router that sent the message with the highest preference as the default gateway. The preference can be a number from
Enabling IRDP Globally
To enable IRDP globally, use either of the following methods.
USING THE CLI
To globally enable IRDP, enter the following command:
HP9300(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.
USING THE WEB MANAGEMENT INTERFACE
1.Log on to the device using a valid user name and password for
2.Click on the plus sign next to Configure in the tree view to display the list of configuration options.
3.Click on the plus sign next to IP to display the list of IP configuration options.
4.Select the General link to display the IP configuration panel.
5.Select Enable next to IRDP.
6.Click the Apply button to save the change to the device’s
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