Cisco IE 4000, Software Configuration Manual

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Configuring IP Unicast Routing
Configuring IP Addressing
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# ip default-gateway 192.31.7.18
Switch(config)# end
ICMP Router Discovery Protocol (IRDP)
Router discovery allows the switch to dynamically learn about routes to other networks using IRDP. IRDP allows hosts to
locate routers. When operating as a client, the switch generates router discovery packets. When operating as a host, the
switch receives router discovery packets. The switch can also listen to Routing Information Protocol (RIP) routing updates
and use this information to infer locations of routers. The switch does not actually store the routing tables sent by routing
devices; it merely keeps track of which systems are sending the data. The advantage of using IRDP is that it allows each
router to specify both a priority and the time after which a device is assumed to be down if no further packets are
received.
Each device discovered becomes a candidate for the default router, and a new highest-priority router is selected when
a higher priority router is discovered, when the current default router is declared down, or when a TCP connection is
about to time out because of excessive retransmissions.
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.
BEFORE YOU BEGIN

The ip irdp multicast 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.

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.