CCNP Certification / BCMSN Examination Tutorial: Getting Started With HSRP
Described in RFC 2281, HSRP is often a Cisco-proprietary protocol through which routers are place into an HSRP router team. Coupled with dynamic routing protocols and STP, HSRP is considered a high-availability network service, since all three have an Practically quick cutover to the secondary route when the key path is unavailable.
One of the routers will be selected as the principal (“Active”, in HSRP terminology), and that Principal will tackle the routing while one other routers are in standby, Completely ready to manage the load if the key router gets unavailable. On this trend, HSRP makes sure a large network uptime, since it routes IP targeted traffic devoid of depending on one router.
The hosts working with HSRP as being a gateway don’t know the particular IP or MAC addresses in the routers during the team. They’re communicating that has a pseudorouter, a “Digital router” established with the HSRP configuration. This Digital router will have a virtual MAC and IP adddress too.
The standby routers aren’t just going to be sitting down there, however! By configuring various HSRP groups on just one interface, HSRP load balancing could be accomplished.
Ahead of we reach the more Innovative HSRP configuration, we far better receive a simple one particular started out! We’ll be using a two-router topology right here, and Take into account that a person or both equally of these routers could be multilayer switches also. For relieve of reading, I’m intending to check with them only as routers.
R2 and R3 will both be configured being in standby team 5. The Digital router will have an IP deal with of 172.12.23.ten /24. All hosts in VLAN one hundred must use this address as their default gateway.
R2(config)#interface ethernet0
R2(config-if)#standby 5 ip 172.12.23.10
R3(config)#interface ethernet0
R3(config-if)#standby five ip 172.12.23.ten
The clearly show command for HSRP is display standby, and it’s the initial command you should run when configuring and troubleshooting HSRP. Permit’s operate it on each routers and Assess final results.
R2#demonstrate standby
Ethernet0 – Group 5
Neighborhood condition 안전놀이터 is Standby, precedence 100
Hellotime 3 sec, holdtime 10 sec
Up coming hello there sent in 0.776
Digital IP tackle is 172.twelve.23.ten configured
Energetic router is 172.twelve.23.three, precedence 100 expires in 9.568
Standby router is local
1 point out alterations, past state improve 00:00:22
R3#clearly show standby
Neighborhood point out is Energetic, precedence 100
Next hi there despatched in two.592
Energetic router is nearby
Standby router is 172.12.23.2 expires in 8.020
Virtual mac address is 0000.0c07.ac05
two condition improvements, past state adjust 00:02:08
We will see that R3 has long been chosen since the Active router (“area point out is Lively”), the Digital router’s IP is 172.twelve.23.ten, and R2 will be the standby router.
Usually there are some HSRP values you’ll need to have to vary every so often. Let's say we would like R2 being the Active router instead? Can we alter the MAC tackle of the Digital router? I’ll answer All those issues in the following portion of the HSRP tutorial!