HSRP Learn state

[lquin1978]

Reading up on HSRP and I saw the following  on the Cisco.com website:

Learn - The router has not determined the virtual IP address and has                     not yet seen an authenticated hello message from the active router. In this                     state, the router still waits to hear from the active router.

So I read the above statment and wondered why would the router not have determined the virtual IP address? as isnt this part of the basic config?  but then I read the following:

Learn parameters—This action is taken when an authenticated                     message is received from the active router. If the virtual IP address for this                     group is not manually configured, the virtual IP address can be learned from                     the message. The router can learn hello time and hold time values from the                     message.

How can HSRP be configured without manually setting the virtual IP??

Thanks in advance

[Rolf Fischer · Accepted solution]

Hi,

you can configure a HSRP interface like this:

interface Vlan1

ip address 192.168.1.3 255.255.255.0

standby 1 ip

!

The virtual IP is advertised in the HSRP Hellos , so if another router on the segment has a virtual IP configured, it can be learned trough received hellos.

Vlan1 - Group 1

State is Standby

1 state change, last state change 00:07:02

Virtual IP address is 192.168.1.1 (learnt)

Active virtual MAC address is 0000.0c07.ac01

Local virtual MAC address is 0000.0c07.ac01 (v1 default)

Hello time 3 sec, hold time 10 sec

Next hello sent in 0.912 secs

Preemption disabled

Active router is 192.168.1.2, priority 100 (expires in 9.864 sec)

Standby router is local

Priority 90 (configured 90)

IP redundancy name is "hsrp-Vl1-1" (default)

HTH

Rolf

Useful link: RFC 2281 - Cisco Hot Standby Router Protocol (HSRP)