CCNP Certification / BCMSN Exam Tutorial: Getting going With HSRP
Described in RFC 2281, HSRP is a Cisco-proprietary protocol where routers are set into an HSRP router group. Along with dynamic routing protocols and STP, HSRP is taken into account a significant-availability network service, since all 3 have an Nearly immediate cutover to a secondary route when the principal route is unavailable.
On the list of routers will probably be picked as the first (“Lively”, in HSRP terminology), and that Main will cope with the routing when another routers are in standby, All set to manage the load if the primary router results in being unavailable. During this style, HSRP guarantees a significant community uptime, as it routes IP traffic without having depending on a single router.
The hosts making use of HSRP like a gateway don’t know the particular IP or MAC addresses in the routers in the team. They’re communicating with a pseudorouter, a “virtual router” established by the HSRP configuration. This Digital router will likely have a virtual MAC and IP adddress also.
The standby routers aren’t just destined to be sitting down there, while! By configuring several HSRP groups on a single interface, HSRP load balancing is usually obtained.
Before we reach the greater State-of-the-art HSRP configuration, we far better have a standard just one commenced! We’ll be utilizing a two-router topology in this article, and Understand that a single or equally of such routers may very well be multilayer switches in addition. For ease of reading through, I’m going to refer to them only as routers.
R2 and R3 will both equally be configured to generally be in standby group 5. The Digital router can have an IP address of 172.12.23.ten /24. All hosts in VLAN one hundred should really use this tackle as their default gateway.
R2(config)#interface ethernet0
R2(config-if)#standby five ip 172.twelve.23.ten
R3(config)#interface ethernet0
R3(config-if)#standby 5 ip 172.12.23.ten
The present command for HSRP is exhibit standby, and it’s the very first command you must run though configuring and troubleshooting HSRP. Permit’s operate it on both routers and Look at success.
R2#demonstrate standby
Ethernet0 – Group five
Community point out is Standby, priority one hundred
Hellotime 3 sec, holdtime ten sec
Future howdy despatched in 0.776
Virtual IP tackle is 172.12.23.ten configured
Lively router is 172.twelve.23.three, precedence a hundred expires in nine.568
Standby router is nearby
1 condition variations, final condition modify 00:00:22
R3#demonstrate standby
Community state is Active, precedence 100
Next hi there despatched in two.592
Active router is neighborhood
Standby router is 172.twelve.23.2 expires in eight.020
Virtual mac address is 0000.0c07.ac05
two point out adjustments, last point out transform 00:02:08
We can see that R3 has been selected as being the Active router (“regional condition is Lively”), the virtual router’s IP is 172.twelve.23.10, and R2 is the standby router.
There are a few HSRP values that you’ll want to vary every so often. Imagine if 토토검증 we wish R2 to generally be the Active router as a substitute? Can we alter the MAC address in the virtual router? I’ll answer These questions in the following part of this HSRP tutorial!