CCNP Certification / BCMSN Test Tutorial: Starting out With HSRP
Described in RFC 2281, HSRP is a Cisco-proprietary protocol in which routers are put into 안전놀이터 an HSRP router team. Coupled with dynamic routing protocols and STP, HSRP is taken into account a large-availability community company, given that all three have an Virtually immediate cutover into a secondary route when the principal path is unavailable.
One of several routers might be selected as the principal (“Active”, in HSRP terminology), Which primary will manage the routing although one other routers are in standby, ready to manage the load if the key router gets unavailable. In this particular trend, HSRP makes certain a large community uptime, because it routes IP traffic without having depending on a single router.
The hosts applying HSRP like a gateway don’t know the particular IP or MAC addresses from the routers inside the team. They’re communicating with a pseudorouter, a “virtual router” designed with the HSRP configuration. This virtual router may have a virtual MAC and IP adddress in addition.
The standby routers aren’t just going to be sitting there, although! By configuring a number of HSRP teams on a single interface, HSRP load balancing can be accomplished.
Right before we reach the greater Sophisticated HSRP configuration, we better get a essential 1 started! We’ll be employing a two-router topology right here, and Understand that just one or each of such routers could be multilayer switches too. For relieve of reading, I’m likely to refer to them only as routers.
R2 and R3 will both be configured for being in standby group 5. The virtual router could have an IP tackle of 172.twelve.23.ten /24. All hosts in VLAN 100 should really use this handle as their default gateway.
R2(config)#interface ethernet0
R2(config-if)#standby 5 ip 172.twelve.23.10
R3(config)#interface ethernet0
R3(config-if)#standby 5 ip 172.twelve.23.10
The show command for HSRP is display standby, and it’s the initial command you ought to run while configuring and troubleshooting HSRP. Enable’s run it on both equally routers and Evaluate outcomes.
R2#show standby
Ethernet0 – Group 5
Community state is Standby, precedence 100
Hellotime three sec, holdtime ten sec
Upcoming hi sent in 0.776
Virtual IP address is 172.twelve.23.10 configured
Energetic router is 172.12.23.3, priority a hundred expires in nine.568
Standby router is regional
1 point out improvements, very last state change 00:00:22
R3#present standby
Local point out is Energetic, precedence a hundred
Upcoming good day sent in 2.592
Active router is nearby
Standby router is 172.twelve.23.two expires in 8.020
Virtual mac handle is 0000.0c07.ac05
2 state alterations, very last state improve 00:02:08
We are able to see that R3 has actually been chosen because the Energetic router (“area point out is Energetic”), the virtual router’s IP is 172.12.23.ten, and R2 would be the standby router.
There are numerous HSRP values you’ll have to have to alter every now and then. Imagine if we would like R2 to get the Active router as an alternative? Can we change the MAC address of your virtual router? I’ll response Those people inquiries in the following element of this HSRP tutorial!