Router Discovery Protocol Commands

This section describes the commands you use to view and configure Router Discovery Protocol settings on the switch. The Router Discovery Protocol enables a host to discover the IP address of routers on the subnet.

ip irdp

This command enables Router Discovery on an interface or range of interfaces.

• Default: disabled
• Format: ip irdp
• Mode: Interface Config

no ip irdp

This command disables Router Discovery on an interface.

• Format: no ip irdp
• Mode: Interface Config

ip irdp address

This command configures the address that the interface uses to send the router discovery advertisements. The valid values for ipaddr are 224.0.0.1, which is the all-hosts IP multicast address, and 255.255.255.255, which is the limited broadcast address.

• Default: 224.0.0.1
• Format: ip irdp address ipaddr
• Mode: Interface Config

no ip irdp address

This command configures the default address used to advertise the router for the interface.

• Format: no ip irdp address
• Mode: Interface Config

ip irdp holdtime

This command configures the value, in seconds, of the holdtime field of the router advertisement sent from this interface. The holdtime range is the value of maxadvertinterval to 9000 seconds.

• Default: 3 * maxinterval
• Format: ip irdp holdtime maxadvertinterval-9000
• Mode: Interface Config

no ip irdp holdtime

This command configures the default value, in seconds, of the holdtime field of the router advertisement sent from this interface.

• Format: no ip irdp holdtime
• Mode: Interface Config

ip irdp maxadvertinterval

This command configures the maximum time, in seconds, allowed between sending router advertisements from the interface. The range for maxadvertinterval is 4 to 1800 seconds.

• Default: 600
• Format: ip irdp maxadvertinterval 4-1800
• Mode: Interface Config

no ip irdp maxadvertinterval

This command configures the default maximum time, in seconds.

• Format: no ip irdp maxadvertinterval
• Mode: Interface Config

ip irdp minadvertinterval

This command configures the minimum time, in seconds, allowed between sending router advertisements from the interface. The range for minadvertinterval is three to the value of maxadvertinterval.

• Default: 0.75 * maxadvertinterval
• Format: ip irdp minadvertinterval 3-maxadvertinterval
• Mode: Interface Config

no ip irdp minadvertinterval

This command sets the default minimum time to the default.

• Format: no ip irdp minadvertinterval
• Mode: Interface Config

ip irdp multicast

This command configures the destination IP address for router advertisements. If no destination IP address is configured, router advertisements are forwarded to 224.0.0.1 by default. You can also configure the IP address as 255.255.255.255 (or use the no form of the command) to instead send router advertisements to the limited broadcast address.

• Format: ip irdp multicast ip address
• Mode: Interface Config

no ip irdp multicast

By default, router advertisements are sent to 224.0.0.1. To instead send router advertisements to the limited broadcast address, 255.255.255.255, use the no form of this command.

• Format: no ip irdp multicast
• Mode: Interface Config

ip irdp preference

This command configures the preferability of the address as a default router address, relative to other router addresses on the same subnet.

• Default: 0
• Format: ip irdp preference -2147483648 to 2147483647
• Mode: Interface Config

no ip irdp preference

This command configures the default preferability of the address as a default router address, relative to other router addresses on the same subnet.

• Format: no ip irdp preference
• Mode: Interface Config

show ip irdp

This command displays the router discovery information for all interfaces, or a specified interface.

• Format: show ip irdp {unit/slot/port | all}
• Modes: Privileged EXEC/User EXEC
• Interface: The unit/slot/port that matches the rest of the information in the row.
• Ad Mode: The advertise mode, which indicates whether router discovery is enabled or disabled on this interface.
• Dest Address: The destination IP address for router advertisements.
• Max Int: The maximum advertise interval, which is the maximum time, in seconds, allowed between sending router advertisements from the interface.
• Min Int: The minimum advertise interval, which is the minimum time, in seconds, allowed between sending router advertisements from the interface.
• Hold Time: The amount of time, in seconds, that a system should keep the router advertisement before discarding it.
• Preference: The preference of the address as a default router address, relative to other router addresses on the same subnet.