Interfaces can be configured with an MD5 encrypted password for authentication, and VRRP-E can use the same authentication type associated with the interfaces on which you define the virtual router.
VRRP Extended (VRRP-E) must be configured on the device and the interface associated with a virtual router group.
Any VRRP-E packets that do not contain the password are dropped. If your interfaces do not use authentication, neither does VRRP-E. Repeat this task on all interfaces on all devices that support the same virtual router group.

Note
VRRP-E is supported on the devices described in this guide. In a mixed-device environment, consult your documentation for the other devices to determine if VRRP-E is supported.device# configure terminal
device(config)# protocol vrrp-extended
device(config)# interface ve 10
device(config-if-Ve-10)# ip vrrp-extended auth-type md5-auth kfhb61qp

Note
MD5 passwords cannot have ASCII character 32 ('SPACE') as a part of the password string.device(config-if-Ve-10)# end
device# show vrrp
Total number of VRRP session(s)   : 1
VRID 1
  Interface: Ve 10;  Ifindex: 1207959562
  Mode: VRRPE
  Admin Status: Enabled
  Description :
  Address family: IPv4
  Version: 2
  Authentication type: MD5 Authentication
  State: Initialize
  Session Master IP Address:
  Virtual IP(s): 192.168.4.100
  Configured Priority: 110 (default: 100); Current Priority: unset
  Advertisement interval: 1 sec  (default: 1 sec)
  Preempt mode: DISABLE  (default: DISABLED)
  Advertise-backup: DISABLE  (default: DISABLED)
  Backup Advertisement interval: 60 sec  (default: 60 sec)
  Short-path-forwarding: Disabled
  Revert Priority: unset; SPF reverted: No
  Hold time: 0 sec  (default: 0 sec)
  Trackport:
    Port(s)                    Priority  Port Status
    =======                    ========  ===========
  Statistics:
    Advertisements: Rx: 0, Tx: 0
    Gratuitous ARP: Tx: 0
 
		  The following example configures MD5 authentication for the specified VRRP-E interface.
device# configure terminal device(config)# protocol vrrp-extended device(config)# interface ve 10 device(config-if-Ve-10)# ip vrrp-extended auth-type md5-auth kfhb61qp device(config-if-Ve-10)# end device# show vrrp