CCNP Certification / BCMSN Test Tutorial: Starting out With HSRP
Defined in RFC 2281, HSRP can be a Cisco-proprietary protocol during which routers are place into an HSRP router team. In addition to dynamic routing protocols and STP, HSRP is considered a significant-availability network service, considering that all three have an Pretty much quick cutover to a secondary route when the principal path is unavailable.
Among the routers is going to be chosen as the key (“Active”, in HSRP terminology), Which Key will manage the routing whilst the opposite routers are in standby, ready to manage the load if the primary router gets unavailable. Within this manner, HSRP ensures a substantial network uptime, since it routes IP targeted traffic without the need of depending on one router.
The hosts making use of HSRP as being a gateway don’t know the actual IP or MAC addresses on the routers from the group. They’re speaking by using a pseudorouter, a “virtual router” produced by the HSRP configuration. This virtual router will likely have a Digital MAC and IP adddress too.
The standby routers aren’t just destined to be sitting down there, even though! By configuring multiple HSRP teams on an individual interface, HSRP load balancing could be achieved.
Right before we reach the more Superior HSRP configuration, we far better get yourself a fundamental one particular started out! We’ll be employing a two-router topology in this article, and Understand that one or the two of these routers may be multilayer switches in addition. 먹튀사이트 For relieve of looking through, I’m planning to seek advice from them only as routers.
R2 and R3 will equally be configured to be in standby group five. The virtual router could have an IP tackle of 172.12.23.ten /24. All hosts in VLAN 100 should use this handle as their default gateway.
R2(config)#interface ethernet0
R2(config-if)#standby 5 ip 172.12.23.ten
R3(config)#interface ethernet0
R3(config-if)#standby five ip 172.twelve.23.10
The show command for HSRP is show standby, and it’s the 1st command you must run when configuring and troubleshooting HSRP. Let’s run it on the two routers and Assess effects.
R2#display standby
Ethernet0 – Team five
Local state is Standby, priority a hundred
Hellotime three sec, holdtime ten sec
Next good day despatched in 0.776
Virtual IP tackle is 172.twelve.23.ten configured
Energetic router is 172.twelve.23.3, priority a hundred expires in 9.568
Standby router is neighborhood
1 state variations, past condition alter 00:00:22
R3#present standby
Area state is Active, precedence one hundred
Subsequent hello despatched in two.592
Lively router is local
Standby router is 172.twelve.23.2 expires in 8.020
Virtual mac tackle is 0000.0c07.ac05
two point out improvements, past condition modify 00:02:08
We are able to see that R3 is picked as the Energetic router (“neighborhood point out is Active”), the Digital router’s IP is 172.12.23.ten, and R2 may be the standby router.
There are a few HSRP values you’ll need to have to vary every so often. Let's say we wish R2 to get the Active router instead? Can we change the MAC address of the virtual router? I’ll reply All those queries in another section of this HSRP tutorial!