3Com SuperStack II 9300 Command Reference Manual page 493

When you define a Primary router on a VLAN that contains a single
interface, the single interface is automatically chosen as the primary
address when you select IP-address as the Address mode.
When you define a Backup virtual router, selecting auto-learn as
the address mode configures the Backup router to learn the IP
addresses that are associated with the virtual router by means of VRRP
advertisements from the Primary router. The Primary router must be up
for backup routers to auto-learn the addresses that are associated
with the specified VRID.
When you define Backup virtual routers, the auto-learn address mode
option enables auto address learning for the specified VRID. If a new
interface is added to the VLAN on a primary virtual router, the new IP
address is sent out in VRRP advertisements so that the Backup routers
in auto-learn mode can learn the new address without having to
manually add the new address to each backup router.
The smaller the advertisement interval, the smaller the failover time if
Advertisement
Intervals the master fails.
The advertisement interval must be the same across the set of VRRP
routers that are associated with a single VRID. Backup routers must
have the same advertisement interval as the Master router.
Options
Prompt
Virtual router type Type of virtual router
VLAN interface
index
VRID
Address mode
Description Possible Values
that you want to
define
Index number of the
virtual LAN (VLAN) on
which you want to
define the virtual
router
Virtual router
identifier. Identifies
the virtual router that
you want to define on
the LAN.
Method by which the
virtual router you
want to define learns
its IP addresses
ip vrrp define
Primary
Backup
Index number of an IP
virtual LAN (VLAN) that
is defined on the
system.
? (for a list of selectable
indexes)
1 – 255
auto-learn
IP address
493
[Default]
Primary
Index
number of
first
available
VLAN
1
auto-learn