CCNP Certification / BCMSN Exam Tutorial: Getting Started With HSRP
Outlined in RFC 2281, HSRP can be a Cisco-proprietary protocol in which routers are set into an HSRP router team. Along with dynamic routing protocols and STP, HSRP is considered a substantial-availability community provider, considering that all 3 have an Nearly rapid cutover to your secondary route when the first path is unavailable.
One of many routers will likely be selected as the primary (“Lively”, in HSRP terminology), Which Key will deal with the routing while the other routers are in standby, Completely ready to take care of the load if the primary router becomes unavailable. On this fashion, HSRP assures a high community uptime, as it routes IP website traffic devoid of relying on a single router.
The hosts using HSRP as being a gateway don’t know the actual IP or MAC addresses of your routers within the group. They’re communicating that has a pseudorouter, a “Digital router” designed with the HSRP configuration. This Digital router will have a virtual MAC and IP adddress at the same time.
The standby routers aren’t just likely to be sitting there, however! By configuring multiple HSRP groups on only one interface, HSRP load balancing can be reached.
Just before we get to the more Superior HSRP configuration, we greater receive a essential a single commenced! We’ll be utilizing a two-router topology here, and keep in mind that just one or equally of such routers could be multilayer switches in addition. For relieve of examining, I’m about to consult with them only as routers.
R2 and R3 will equally be configured to generally be in standby group 5. The virtual router will have an IP tackle of 172.12.23.ten /24. All hosts in VLAN 100 ought to use this handle 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.twelve.23.ten
The exhibit command for HSRP is clearly show standby, and it’s the very first command you should run though configuring and troubleshooting HSRP. Let’s operate it on both of those routers and Examine benefits.
R2#show standby
Ethernet0 – Group five
Nearby state is Standby, precedence 100
Hellotime three sec, holdtime 10 sec
Next good day sent in 0.776
Virtual IP handle is 172.12.23.ten configured
Active router is 172.12.23.three, priority a hundred expires in 9.568
Standby router is nearby
1 point out changes, previous condition change 00:00:22
R3#clearly show standby
Regional state is Active, precedence one hundred
Future howdy despatched in two.592
Lively router is neighborhood
Standby router is 172.12.23.2 expires in eight.020
Digital mac tackle is 0000.0c07.ac05
two state variations, final point out improve 00:02:08
We can see that R3 is picked as being the Lively router (“regional condition is Active”), the virtual router’s IP is 172.twelve.23.ten, and R2 will be the standby router.
There are many HSRP values that you just’ll have to have to vary every so often. What if we want R2 to get the Energetic router in its place? Can we alter the MAC tackle of 먹튀사이트 your Digital router? I’ll solution those concerns in the following portion of the HSRP tutorial!