How to Troubleshoot Apps for the Modern Connected Worker
Hsrp
1. Anuj Kumar
ciscobulls@gmail.com
CCNP SWITCH
PORTABLE STUDY GUIDE
&
PRACTICE WORK BOOK
ANUJ KUMAR
email:- ciscobulls@gmail.com
anuj_dev007@yahoo.com
networkbulls.com
2. Anuj Kumar
ciscobulls@gmail.com
REDUNDANCY PROTOCOLS
Cisco IOS offers feature to provide a redundant default gateway to end devices. The following are the default
gateway features supported by Cisco IOS and switches.
Hot Standby Routing Protocol (HSRP)
Virtual Router Redundancy Protocol (VRRP)
Gateway Load Balancing Protocol (GLBP)
HSRP (Hot Standby Routing Protocol)
Feature:-
It is Cisco proprietary protocol.
It uses UDP Port no 1985
It sends hello message on multicast address 224.0.0.2
It sends out hello message every 3 sec (hold timer 10 sec)
Priority by default 100
It supports two types of authentication.
It supports tracking.
HSRP States: -
Active State: - in this active state, the router is send packets that are sent to virtual MAC and IP address of the
HSRP group. The active router also sends periodic hello message.
Standby: - in this state, the HSRP router is the next active router and it send periodic hello message. There must
be at least one standby router in the HSRP group.
Note: - A router does not hear any higher priority that router assume itself, so promote itself standby router.
A router does not hear an active router, so promote itself active router.
When the preempt option is not configure, the first router to initialize HSRP becomes the active router.
Configuration of HSRP on Switch
Switch1(config)#interface vlan 10
Switch1(config-if)#ip address 192.168.101.2 255.255.255.0
Switch1(config-if)#standby 1 ip 192.168.101.1
Switch1(config-if)#standby priority 150
Switch1(config-if)#standby 1 preempt
Switch2(config)#interface vlan 10
Switch2(config-if)#ip address 192.168.101.3 255.255.255.0
Switch2(config-if)#standby 1 ip 192.168.101.1
Switch2(config-if)#standby priority 200
Switch2(config-if)#standby 1 preempt
3. Anuj Kumar
ciscobulls@gmail.com
Load Balancing of HSRP
While a router is actively forwarding traffic for one HSRP group, it can be in the standby or listen state for another
group.
Router A & Router B should be members of group 1 & Group 2.
Like as: -
Router A:
Active forwarding router for group 1
Standby router for group 2.
Router B:
Active forwarding router for group 2
Standby router for group 1.
Example:
Switch1(config)#interface vlan 10
Switch1(config-if)#ip address 192.168.101.2 255.255.255.0
Switch1(config-if)#standby 1 ip 192.168.101.1
Switch1(config-if)#standby priority 150
Switch1(config-if)#standby 1 preempt
Switch1(config)#interface vlan 20
Switch1(config-if)#ip address 192.168.102.2 255.255.255.0
Switch1(config-if)#standby 1 ip 192.168.102.1
Switch1(config-if)#standby priority 200
Switch1(config-if)#standby 1 preempt
Switch2(config)#interface vlan 10
Switch2(config-if)#ip address 192.168.101.3 255.255.255.0
Switch2(config-if)#standby 1 ip 192.168.101.1
Switch2(config-if)#standby priority 200
Switch2(config-if)#standby 1 preempt
Switch2(config)#interface vlan 20
Switch2(config-if)#ip address 192.168.102.3 255.255.255.0
Switch2(config-if)#standby 1 ip 192.168.102.1
Switch2(config-if)#standby priority 150
Switch2(config-if)#standby 1 preempt
Timers:-
Both the hellotime and the holdtime parameters are configurable.
Switch(config-if)#standby group-number timers hellotime holdtime
Hellotime
Default = 3 seconds
Value varies from 1 to 255.
Holdtime
Default = 10 seconds
Value varies from 1 to 255.
4. Anuj Kumar
ciscobulls@gmail.com
To reinstate the default standby timer values, enter the following command:
Switch(config-if)#no standby group-number timers
Configuring HSRP Interface Tracking
The f0/0 interfaces on router A tracks the S0/0 interface. If the link between the S0/0 interface and Core fails, the
router automatically decrements its priority (10) on that interface and stops transmitting hello messages out
interface f0/0. Router B assumes the active router role when no hello messages are detected for the specific
holdtime period.
Switch1(config)#interface vlan 10
Switch1(config-if)#ip address 192.168.101.2 255.255.255.0
Switch1(config-if)#standby 1 ip 192.168.101.1
Switch1(config-if)#standby priority 150
Switch1(config-if)#standby 1 preempt
Switch1(config-if)#standby 1 track serial0/0(self interface name)
Switch2(config)#interface vlan 10
Switch2(config-if)#ip address 192.168.101.3 255.255.255.0
Switch2(config-if)#standby 1 ip 192.168.101.1
Switch2(config-if)#standby priority 200
Switch2(config-if)#standby 1 preempt
Switch2(config-if)#standby 1 track serial0/0 (self interface name)
Practical
6. Anuj Kumar
ciscobulls@gmail.com
SW2(config-router)#int f0/0
SW2(config-if)#standby 1 ip 192.168.101.1
SW2(config-if)#standby 1 priority 200
SW2(config-if)#standby 1 preempt
*Mar 1 00:34:31.431: %HSRP-5-STATECHANGE: FastEthernet0/0 Grp 1 state
Standby -> Active
SW2(config-if)#standby 1 track serial 0/0
Verifying
SW1#sh standby
FastEthernet0/0 - Group 1
State is Standby
4 state changes, last state change 00:43:18
Virtual IP address is 192.168.101.1
Active virtual MAC address is 0000.0c07.ac01
Local virtual MAC address is 0000.0c07.ac01 (v1 default)
Hello time 3 sec, hold time 10 sec
Next hello sent in 0.000 secs
Preemption enabled
Active router is 192.168.101.3, priority 190 (expires in 6.912 sec)
Standby router is local
Priority 150 (configured 150)
Track interface Serial0/0 state Up decrement 10
Group name is "hsrp-Fa0/0-1" (default)
SW2#sh standby
FastEthernet0/0 - Group 1
State is Active
2 state changes, last state change 00:44:28
Virtual IP address is 192.168.101.1
Active virtual MAC address is 0000.0c07.ac01
Local virtual MAC address is 0000.0c07.ac01 (v1 default)
Hello time 3 sec, hold time 10 sec
Next hello sent in 1.296 secs
Preemption enabled
Active router is local
Standby router is 192.168.101.2, priority 150 (expires in 8.436 sec)
Priority 190 (configured 200)
Track interface Serial0/0 state Down decrement 10
Group name is "hsrp-Fa0/0-1" (default)
Thank you for giving me your precious time.
Anuj Kumar
