CCNP Certification / BCMSN Exam Tutorial: Getting Started With HSRP
Computer and Technology - Defined in RFC 2281, HSRP is a Cisco-proprietary protocol during which routers are put into an HSRP router group. Together with dynamic routing protocols and STP, HSRP is taken into account a high-availability network service, since all three have an almost immediate cut over to some secondary path once the primary path is unavailable.
Perhaps one of the routers will certainly be selected as the primary "Active," in HSRP terminology ), which primary will handle the routing while other routers are actually on standby, able to handle the load when the primary router becomes unavailable. During this fashion, HSRP ensures a higher network uptime, because it routes IP traffic without counting on one router.
The hosts using HSRP like a gateway do not know the particular IP or MAC addresses from the routers inside the group. They are communicating having a pseudo router, a "virtual router" created from the HSRP configuration. This virtual router will possess a virtual MAC and IP address also.
The standby routers are not just likely going to be sitting there, though! By configuring multiple HSRP groups on one interface, HSRP load balancing could be achieved.
Before we arrive at the more advanced HSRP configuration, we better obtain a basic one started! We will be employing a two-router topology here, and remember that one or both of those routers could be multilayer switches also. For simple reading, I am visiting refer for them only as routers.
R2 and R3 will both be configured to have standby group 5. The virtual router may have an IP address of 172. 12. 23. 10 / 24. All hosts in VLAN 100 should make use of this address as their default gateway.
R2 (config ) #interface ethernet0
R2 (config-if ) #standby 5 ip 172. 12. 23. 10
R3 (config ) #interface ethernet0
R3 (config-if ) #standby 5 ip 172. 12. 23. 10
The show command for HSRP is shown standby; then it‘s the very first command you ought to run while configuring and troubleshooting HSRP. Let us run it on both routers and compare results.
R2#show standby
Ethernet0 - Group 5
Local state is Standby, priority 100
Hello time 3 sec, hold time 10 sec
Next hello sent in 0. 776
The virtual IP address is 172. 12. 23. 10 configured
Active router is 172. 12. 23. 3, priority 100 expires in 9. 568
Standby router is local
One state changes, last state change 00: 00: 22
R3#show standby
Ethernet0 - Group 5
Local state is Active, priority 100
Hello time 3 sec, hold time 10 sec
Next hello sent in 2. 592
The virtual IP address is 172. 12. 23. 10 configured
Active router is local
Standby router is 172. 12. 23. 2 expires in 8. 020
Virtual mac address is 0000. 0c07. ac05
Two state changes, last state change 00: 02: 08
We will see that R3 is selected as the Active router "local state is Active", the virtual router's IP is 172. 12. 23. 10, and R2 is that the standby router.
Usually, there are some HSRP values that you will need to alter from time for them to time. Imagine we want R2 as being Active router instead? Can we affect the MAC address from the virtual router? I am going to answer those questions in the subsequent section of this HSRP tutorial!
I think it's enough all about CCNP Certification / BCMSN Exam Tutorial: Getting Started With HSRP. Thanks so much :)
CCNP Certification / BCMSN Exam Tutorial: Getting Started With HSRP
Perhaps one of the routers will certainly be selected as the primary "Active," in HSRP terminology ), which primary will handle the routing while other routers are actually on standby, able to handle the load when the primary router becomes unavailable. During this fashion, HSRP ensures a higher network uptime, because it routes IP traffic without counting on one router.
The hosts using HSRP like a gateway do not know the particular IP or MAC addresses from the routers inside the group. They are communicating having a pseudo router, a "virtual router" created from the HSRP configuration. This virtual router will possess a virtual MAC and IP address also.
The standby routers are not just likely going to be sitting there, though! By configuring multiple HSRP groups on one interface, HSRP load balancing could be achieved.
Before we arrive at the more advanced HSRP configuration, we better obtain a basic one started! We will be employing a two-router topology here, and remember that one or both of those routers could be multilayer switches also. For simple reading, I am visiting refer for them only as routers.
R2 and R3 will both be configured to have standby group 5. The virtual router may have an IP address of 172. 12. 23. 10 / 24. All hosts in VLAN 100 should make use of this address as their default gateway.
R2 (config ) #interface ethernet0
R2 (config-if ) #standby 5 ip 172. 12. 23. 10
R3 (config ) #interface ethernet0
R3 (config-if ) #standby 5 ip 172. 12. 23. 10
The show command for HSRP is shown standby; then it‘s the very first command you ought to run while configuring and troubleshooting HSRP. Let us run it on both routers and compare results.
R2#show standby
Ethernet0 - Group 5
Local state is Standby, priority 100
Hello time 3 sec, hold time 10 sec
Next hello sent in 0. 776
The virtual IP address is 172. 12. 23. 10 configured
Active router is 172. 12. 23. 3, priority 100 expires in 9. 568
Standby router is local
One state changes, last state change 00: 00: 22
R3#show standby
Ethernet0 - Group 5
Local state is Active, priority 100
Hello time 3 sec, hold time 10 sec
Next hello sent in 2. 592
The virtual IP address is 172. 12. 23. 10 configured
Active router is local
Standby router is 172. 12. 23. 2 expires in 8. 020
Virtual mac address is 0000. 0c07. ac05
Two state changes, last state change 00: 02: 08
We will see that R3 is selected as the Active router "local state is Active", the virtual router's IP is 172. 12. 23. 10, and R2 is that the standby router.
Usually, there are some HSRP values that you will need to alter from time for them to time. Imagine we want R2 as being Active router instead? Can we affect the MAC address from the virtual router? I am going to answer those questions in the subsequent section of this HSRP tutorial!
I think it's enough all about CCNP Certification / BCMSN Exam Tutorial: Getting Started With HSRP. Thanks so much :)
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