Kenner

To earn your CCNP accreditation and pass the BCMSN test, you have got to know very well what HSRP does and the many configurable options. As the function of HSRP is very simple (and included in a previous tutorial), in addition you need to know how HSRP finds the MAC address for the virtual router - along with how to manage a fresh MAC for this virtual router. This puts us in the unusual position of making a physical address for a switch that doesn't exist!

The output of show standby for a two-router HSRP setup is shown below.

R2#show standby

Ethernet0 - Group 5

Regional state is Standby, concern 100

Hellotime three sec, holdtime 10 sec

Next hello submitted 0.776

Virtual IP is 172.12.23.10 constructed

Effective modem is 172.12.23.3, concern 100 ends in 9.568

Life hub is local

1 state improvements, last state change 00:00:22

R3#show life

Ethernet0 - Group 5

Regional state is Active, concern 100

Hellotime 3 sec, holdtime 10 sec

Next hello sent in 2.592

Virtual IP is 172.12.23.10 configured

Effective switch is local

Standby modem is 172.12.23.2 finishes in 8.020

Electronic macintosh target is 0000.0c07.ac05

2 state improvements, last state change 00:02:08

R3 is in Active state, while R2 is in Standby. The hosts are using the 172.12.123.10 target as their entry, but R3 is in fact managing the workload. R2 will require over if R3 becomes unavailable.

An IP address was given to the virtual switch during the HSRP setting approach, however, not a MAC address. Nevertheless, there is a MAC address beneath the show life result on R3, the active router. How did the HSRP process arrive at a MAC of 00-00-0c-07-ac-05?

Well, all of the work has already been done before the arrangement is also started. The MAC address 00-00-0c-07-ac-xx is reserved for HSRP, and xx is the class number in hexadecimal. That is a good skill to own for the exam, so ensure you are confident with hex conversions. The group number is 5, which can be expressed as 05 with a two-bit hex character. If the group number had been 17, we'd see 11 by the end of the MAC address - one unit of 16, one unit of 1.

The output of the show standby command also tells us that the HSRP speakers are sending Hellos every three seconds, with a 10-second holdtime. These values can be changed with the standby demand, but HSRP speakers in the same party should have the same timers. You may also tie down the hello time and energy to the millisecond, nonetheless it is doubtful you'll actually need to do that.

R3( config-if )#standby 5 timers??

<1-254>Hello interval in seconds

msec Specify hello period in milliseconds

R3( config-if )#standby 5 timers 4??

<5-255>Hold amount of time in seconds

R3( config-if )#standby 5 timers 4 12

Another important HSRP skill is understanding how to change the Active router job. I'll demonstrate how to do that, and how to arrange HSRP interface tracking, next part of my CCNP / BCMSN examination guide! utah web development