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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter22 Configuring IP Unicast Routing
Configuring IP Addressing
The only required task for IRDP routing on an interface is to enable IRDP processing on that interface.
When enabled, the default parameters apply. You can optionally change any of these parameters.
Beginning in privileged EXEC mode, follow these steps to enable and configure IRDP on an interface:
If you change the maxadvertinterval value, the holdtime and minadvertinterval values also change,
so it is important to first change the maxadvertinterval value, before manually changing either the
holdtime or minadvertinterval values.
Use the no ip irdp interface configuration command to disable IRDP routing.
This is an example of output from the show ip irdp privileged EXEC command that shows that IRDP
routing is enabled on Gigabit Ethernet interface 0/3:
Switch# show ip irdp
Vlan1 has router discovery disabled
Vlan2 has router discovery disabled
GigabitEthernet0/1 has router discovery disabled
GigabitEthernet0/2 has router discovery disabled
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 interface interface-id Enter interface configuration mode, and specify the Layer 3 interface to
configure.
Step3 ip irdp Enable IRDP processing on the interface.
Step4 ip irdp multicast (Optional) Send IRDP advertisements to the multicast address
(224.0.0.1) instead of IP broadcasts.
Note This command allows for compatibility with Sun Microsystems
Solaris, which requires IRDP packets to be sent out as multicasts.
Many implementations cannot receive these multicasts; ensure
end-host ability before using this command.
Step5 ip irdp holdtime seconds (Optional) Set the IRDP period for which advertisements are valid. The
default is three times the maxadvertinterval value. It must be greater
than maxadvertinterval and cannot be greater than 9000 seconds. If you
change the maxadvertinterval value, this value also changes.
Step6 ip irdp maxadvertinterval seconds (Optional) Set the IRDP maximum interval between advertisements. The
default is 600 seconds.
Step7 ip irdp minadvertinterval seconds (Optional) Set the IRDP minimum interval between advertisements. The
default is 0.75 times the maxadvertinterval. If you change the
maxadvertinterval, this value changes to the new default (0.75 of
maxadvertinterval).
Step8 ip irdp preference number (Optional) Set a device IRDP preference level. The allowed range is –231
to 231. The default is 0. A higher value increases the router preference
level.
Step9 ip irdp address address [number] (Optional) Specify an IRDP address and preference t o proxy -a dve rtis e.
Step10 end Return to privileged EXEC mode.
Step11 show ip irdp Verify settings by displaying IRDP values.
Step12 copy running-config startup-config (Optional) Save your entries in the configuration file.