Hot Standby Router Protocol HSRP configuration on GNS3:

HSRP is a Cisco proprietary redundancy protocol.  The protocol establishes a framework between network devices in order to achieve default gateway fail-over if the primary gateway should become inaccessible. In HSRP only one device is active as a gateway while other is in standby state. If the active gateway goes down then other standby device take over. This can be useful for dual branch routers each with a single serial link back to the head end.
For HSRP configuration in gns3 I use a simple topology of three switches. For all switch i use the 3640 router IOS with NM-16ESW  module(use a switch in gns3). Switch S-A and S-B are belong to HSRP standby group 1 with IP 10.1.1.10. In HSRP one device is active as a gateway for access devices while other is in standby. The device which have high HSRP priority become active, by default all devices have priority of 100. In our topology I have set a high priority for S-A therefore it is active. Standby group 1 is responsible for changing status of devices as active and standby.  

Switch S-A-configuration:

S-A>en

S-A#configure t

S-A(config)#line vty 0 4

S-A(config-line)#password cisco

S-A(config)#int f0/0

S-A(config-if)#switchport mode trunk

S-A(config)#interface vlan 70

S-A(config-if)#ip address 10.1.1.1 255.255.255.0

S-A(config-if)#no shut

S-A(config-if)#standby 1 ip 10.1.1.10

S-A(config-if)#standby 1 priority 150

Switch S-B-configuration:

S-B(config)#line vty 0 4

S-B(config-line)#password cisco

S-B(config)#int f0/0

S-B(config-if)#switchport mode trunk

S-B(config-if)#no shu

S-B(config)#int f0/1

S-B(config-if)#switchport mode trunk

S-B(config-if)#switchport mode trunk

S-B(config-if)#ex

S-B(config)#interface vlan 70

S-B(config-if)#ip address 10.1.1.2 255.255.255.0

S-B(config-if)#no shut

S-B(config-if)#standby 1 ip 10.1.1.10

S-B#wr

Building configuration...

[OK]

 

R-C configuration

R-C#vlan database

R-C(vlan)#vlan 70

R-C(vlan)#exit

R-C#config t

R-C(config)#int  f0/0

R-C(config-if-range)#switchport access vlan 70

R-C(config-if-range)#switchport mode access

R-C(config)#int  f0/2

R-C(config-if-range)#switchport mode trunk

R-C(config)#int  f0/3

R-C(config-if-range)#switchport mode trunk

Qemu1 Configuration

tc@box:$ sudo su 
root@box:$ Ifconfig eth0 10.1.1.200 netmask 255.255.255.0

root@box:$ Route add default gw 10.1.1.2 eth0

 Verification:

1.  Telnet 10.1.1.10 for qemu1, 10.1.1.10 is standby group 1 IP address and is belong to active device. Since S-A have high priority therefore S-A is gateway for qemu1 even we hard coded qemu1 GW 10.1.1.2 which is S-B. Result: Telnet 10.1.1.10 login into S-A.
2. Now to verify that standby device become active on fail-over stop the S-A and after 30s telnet 10.1.1.10 you should be in S-B.

Useful link: VRRP configuration on GNS3
Thanks...