CCNP Certification / BCMSN Examination Tutorial: Getting Started With HSRP
Described in RFC 2281, HSRP is often a Cisco-proprietary protocol where routers are set into an HSRP router team. Coupled with dynamic routing protocols and STP, HSRP is taken into account a high-availability community company, considering the fact that all 3 have an Virtually immediate cutover to the secondary route when the key route is unavailable.
One of many routers will likely be picked as the primary (“Active”, in HSRP terminology), Which Key will deal with the routing whilst one other routers are in standby, Completely ready to handle the load if the primary router gets unavailable. Within this style, HSRP ensures a substantial community uptime, as it routes IP website traffic with out counting on one router.
The hosts employing HSRP as a gateway don’t know the particular IP or MAC addresses of your routers while in the group. They’re speaking using a pseudorouter, a “virtual router” created with the HSRP configuration. This Digital router can have a Digital MAC and IP adddress at the same time.
The standby routers aren’t just going to be sitting there, even though! By configuring many HSRP teams on just one interface, HSRP load balancing is often obtained.
Just before we get to the more Highly developed HSRP configuration, we far better obtain a primary a person started! We’ll be employing a two-router topology here, and Understand that one or both equally of such routers may very well be multilayer switches as well. For ease of reading through, I’m about to check with them only as routers.
R2 and R3 will both be configured for being in standby team 5. The virtual router can have an IP handle 안전놀이터 of 172.12.23.ten /24. All hosts in VLAN a hundred must use this tackle as their default gateway.
R2(config)#interface ethernet0
R2(config-if)#standby 5 ip 172.twelve.23.ten
R3(config)#interface ethernet0
R3(config-if)#standby 5 ip 172.12.23.10
The show command for HSRP is present standby, and it’s the first command you must operate whilst configuring and troubleshooting HSRP. Let’s run it on the two routers and Evaluate benefits.
R2#demonstrate standby
Ethernet0 – Group five
Local point out is Standby, priority a hundred
Hellotime 3 sec, holdtime 10 sec
Up coming hello there sent in 0.776
Digital IP deal with is 172.12.23.ten configured
Lively router is 172.twelve.23.3, priority one hundred expires in nine.568
Standby router is area
1 state improvements, previous condition adjust 00:00:22
R3#display standby
Regional point out is Energetic, precedence 100
Up coming hi despatched in 2.592
Active router is regional
Standby router is 172.12.23.two expires in eight.020
Virtual mac deal with is 0000.0c07.ac05
two state improvements, previous condition adjust 00:02:08
We will see that R3 has long been selected as being the Energetic router (“regional point out is Active”), the Digital router’s IP is 172.twelve.23.ten, and R2 is the standby router.
Usually there are some HSRP values you’ll want to vary every now and then. Imagine if we want R2 to be the Energetic router as a substitute? Can we alter the MAC address of your virtual router? I’ll respond to All those concerns in the following portion of this HSRP tutorial!