HSRP Configuration With GNS3_ Step by Step _ NetJNL

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HSRP configuration with GNS3: Step by step

By javiernl90 on August 10, 2013 i3 Votes

You can find the spanish post in: Configuracin de HSRP en GNS3 (Asegurando alta disponibilidadde routers Cisco): Paso a paso (h+ps://netjnl.wordpress.com/2013/08/03/hot-standby-router-protocol-hsrp-configuracion-por-gns3/)

What is HSRP (Hot Standby Router Protocol)?

It is a layer 3 protocol of the OSI model, developed by Cisco to provide redundancy at this level andat the Gateway, between two or more Cisco devices.

HSRP uses a virtual MAC and IP address, which used in the event of a failure in any of theconfigured routers.

Operation

It uses a router in Active mode (primary) and another in Standby mode (secondary).

These routers communicate by sending packets hello, from the primary router to router set tostandby. If for a certain time the primary router doesnt send any packets, the secondary router willbe active, taking responsibility for the configured virtual IP.

HSRP configuration with GNS3: Step by step | NetJNL https://netjnl.wordpress.com/2013/08/10/hsrp-configuration-with-gns3-...

1 de 6 14-04-2015 10:15

There are five states in HSRP:

Initial: Is the initial state of the router when the interface is lifted.1.

Listen: It just listen packets hello and knows the virtual IP.2.

Speak: In this state, its may send packets hello and participate to the choice of primary router

(Active) or secundario (Passive).

3.

Standby: Is the router in passive mode but it can switch to active mode when the circumstances

change.

4.

Active: It is the primary router responsible for sending packets to the configured virtual IP.5.

Configuration

The example set by GNS3 tool, has the following schema:

(h+ps://netjnl.files.wordpress.com/2013/08/hsrp.png)

The configuration of routers 2 and 4, which are respectively in Active mode (primary) and Standby(secondary), is the following

R2(config)#int f0/0

R2(config-if)#ip address 10.0.0.2 255.255.255.248

R2(config-if)#standby ip 10.0.0.4

R2(config-if)#standby preempt

R2(config-if)#no shutdown

R2(config-if)#exit

R2(config)#exit

R2#wr

The virtual IP will be 10.0.0.4

The standby mode of preempt, makes the router with the highest priority becomes the activerouter. In the event that both priorities are the same, then the router with the highest IP address willbecome the active router.

The priority by default is 100.

Se+ings are saved with the command wr


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R4#configure terminal

R4(config)#int f0/0

R4(config-if)#ip add 10.0.0.3 255.255.255.248

R4(config-if)#standby 0 ip 10.0.0.4

R4(config-if)#standby priority 99

R4(config-if)#no shutdown

R4(config-if)#exit

R4(config)#exit

R4#wr

Building configuration...[OK]

The priority by default is 100, so to ensure that it has lower priority than the active router it must belower. In this case 99 for example

Se+ings are saved with the command wr

You must repeat the same process for the other subnet (10.0.0.8), followingthe same steps.

The router configurations 1 and 3, follow the same basic configuration asexplained in: Configurar una red de routers Cisco con GNS3(https://netjnl.wordpress.com/2013/08/01/configuracion-de-red-en-routers-cisco/)

Check configuration

To verify configuration, proceed to see the configuration of the router 4 by the command showstandby before and after connecting the router 2.

Before disconnecting R2, it shows how their state is Standby among other parameters:


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R4#show standby

FastEthernet0/0 - Group 0State is Standby

4 state changes, last state change 00:00:18Virtual IP address is 10.0.0.4

/***********Salida omitida**********/Active router is 10.0.0.2, priority 100 (expires in 7.948 sec)Standby router is localPriority 99 (configured 99)

After disconnecting the router 2 router, it is shown as active router and it also shows how the routerin standby status is unknown. Since there are none at the moment:

R4#show standby

FastEthernet0/0 - Group 0State is Active

/******Salida omitida****/Active router is localStandby router is unknown

Priority 99 (configured 99)IP redundancy name is "hsrp-Fa0/0-0" (default)FastEthernet0/1 - Group 0

You can also check the configuration, it can show the current configuration using the commandshow running-config for example Router 2:

interface FastEthernet0/0 ip address 10.0.0.2 255.255.255.248 duplex auto speed auto standby ip 10.0.0.4 standby preempt!interface FastEthernet0/1 ip address 10.0.0.9 255.255.255.248 duplex auto speed auto standby ip 10.0.0.12 standby preempt!

Current router configuration 4:


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interface FastEthernet0/0 ip address 10.0.0.3 255.255.255.248 duplex auto speed auto standby ip 10.0.0.4 standby priority 99!interface FastEthernet0/1 ip address 10.0.0.10 255.255.255.248 duplex auto speed auto standby ip 10.0.0.12 standby priority 99!

Check Connection

It verifies the connection of Router 1 to the other network, with routers 2 and 4 connected ordisconnected any of them:

R1#ping 10.0.0.10

Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 10.0.0.10, timeout is 2 seconds:!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 20/59/96 msR1#ping 10.0.0.12

Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 10.0.0.12, timeout is 2 seconds:!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 28/58/88 ms

You should also check the connection in the opposite way from the router 3 to 1.

Javier Nieto Len

REFERENCES


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h+p://www.networksorcery.com/enp/protocol/hsrp.htm (h+p://www.networksorcery.com/enp/protocol/hsrp.htm)

h+p://www.redescisco.net/v2/art/redundancia-entre-routers-con-hsrp/ (h+p://www.redescisco.net/v2/art/redundancia-entre-routers-con-hsrp/)

h+p://www.ciscopress.com/articles/article.asp?p=766858&seqNum=4 (h+p://www.ciscopress.com/articles/article.asp?p=766858&seqNum=4)

h+p://www.gns3.net/ (h+p://www.gns3.net/)

h+p://www.cisco.com/ (h+p://www.cisco.com/)

Posted in: Cisco, GNS3, Networks, Protocols | Tagged: Cisco, Cisco Systems, Gateway, Hot StandbyRouter Protocol, IP address, MAC address, Router, Standby Router Protocol, Virtual IP address

One response

Configuracin de HSRP en GNS3 (Asegurando alta disponibilidad de routers Cisco): Paso apaso | NetJNL August 13, 2013 at 10:04 am | Reply[] Se puede encontrar el post en Ingls en: HSRP configuration with GNS3: Step by step []

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