High Availability Commands for CCNP BCMSN
- Hot Standby Routing Protocol
- Virtual Router Redundancy Protocol
- Gateway Load Balancing Protocol
- Configuration Example: HSRP
- Configuration Example: GLBP
This chapter provides information and commands concerning the following topics:
- Hot Standby Routing Protocol (HSRP)
- —Configuring HSRP
- —Verifying HSRP
- —HSRP optimization options
- —Debugging HSRP
- Virtual Router Redundancy Protocol (VRRP)
- —Configuring VRRP
- —Verifying VRRP
- —Debugging VRRP
- Gateway Load Balancing Protocol (GLBP)
- —Configuring GLBP
- —Verifying GLBP
- —Debugging GLBP
Hot Standby Routing Protocol
The Hot Standby Router Protocol (HSRP) provides network redundancy for IP networks, ensuring that user traffic immediately and transparently recovers from first-hop failures in network edge devices or access circuits.
Configuring HSRP
Router(config)#interface fastethernet 0/0 |
Moves to interface configuration mode |
Router(config-if)# ip address 172.16.0.10 255.255.255.0 |
Assigns IP address and netmask |
Router(config-if)# standby 1 ip 172.16.0.1 |
Activates HSRP group 1 on the interface and creates a virtual IP address of 172.16.0.1 for use in HSRP |
Router(config-if)# standby 1 priority 120 |
Assigns a priority value of 120 to standby group 1 |
Verifying HSRP
Router# show running-config |
Displays what is currently running on the router |
Router# show standby |
Displays HSRP information |
Router# show standby brief |
Displays a single-line output summary of each standby group |
Router# show standby 1 |
Displays HSRP group 1 information |
Router# show standby fastethernet 0/0 |
Displays HSRP information for the specified interface |
Router# show standby fastethernet 0/0 brief |
Displays a summary of HSRP for the specified interface |
Router# show standby fastethernet 0/0 1 |
Displays HSRP group 1 information for the specified interface |
HSRP Optimization Options
There are options available that make it possible to optimize HSRP operation in the campus network. The next three sections explain three of these options: standby preempt, message timers, and interface tracking.
Preempt
Router(config)# interface fastethernet 0/0 |
Moves to interface configuration mode |
Router(config-if)# standby 1 preempt |
This router will preempt, or take control of, the active router if the local priority is higher than the active router |
Router(config-if)# standby 1 preempt delay minimum 180 |
Causes the local router to postpone taking over as the active router for 180 seconds since that router was last restarted |
Router(config-if)# standby 1 preempt delay reload |
Allows for preemption to occur only after a router reloads |
Router(config-if)# no standby 1 preempt delay reload |
Disables the preemption delay, but preemption itself is still enabled. Use the no standby x preempt command to eliminate preemption |
HSRP Message Timers
Router(config)# interface fastethernet 0/0 |
Moves to interface config mode |
Router(config-if)# standby 1 timers 5 15 |
Sets the hello timer to 5 seconds and sets the hold timer to 15 seconds |
Router(config-if)# standby 1 timers msec 200 msec 600 |
Sets the hello timer to 200 milliseconds and sets the hold timer to 600 milliseconds |
Interface Tracking
Router(config)# interface fastethernet 0/0 |
Moves to interface configuration mode |
Router(config-if)# standby 1 track serial 0/0 25 |
HSRP will track the availability of interface serial 0/0. If serial 0/0 goes down, the priority of the router in group 1 will be decremented by 25. |
Debugging HSRP
Router# debug standby |
Displays all HSRP debugging information, including state changes and transmission/reception of HSRP packets |
Router# debug standby errors |
Displays HSRP error messages |
Router# debug standby events |
Displays HSRP event messages |
Router# debug standby events terse |
Displays all HSRP events except for hellos and advertisements |
Router# debug standby events track |
Displays all HSRP tracking events |
Router# debug standby packets |
Displays HSRP packet messages |
Router# debug standby terse |
Displays all HSRP errors, events, and packets, except for hellos and advertisements |