Configuration verification of HSRP protocol, What is Preempt, How to track If WAN interface down
Configuration verification of HSRP protocol, What is Preempt, How to track If WAN interface down.
It is an application layer (layer 7) protocol.
It is a UDP based protocol which uses port number 1985 at layer 4 of OSI model.
It uses multicast address;
a.) 224.0.0.2 (in case of version 1 (this version allows group number range from 0 to 2553)
b.) 224.0.0.102 (in case of version 2 (this version allows group number range from 0 to
4095)
For Example - For HSRP group number 10, the virtual MAC address will be 0000.0c07.ac0A
There are two types of timer we have;
1.) Hello timer: 03 seconds
2.) Hold timer: 10 second
Election criteria will be based on for the active router;
a.) highest priority value
b.) highest IP address
By default priority value will be 100.
Premption will be disable by default for the active routers but not for the standby routers.
By default track will be inbuilt in case of HSRP.
By default decrement will be 10 in priority value.
It supports two types of authentication:- plain text and MD5
There are total six states we have in case of HSRP protocol:-
1.) Disable: when link is down or port is administratively disabled.
2.) INIT: HSRP is configured and when first time link comes up.
3.) Listen: Router listens to other router's hello messages and router knows the virtual ip
address.
4.) Speak: In this state the election takes place for active and standby router