standby ip




standby [group-number] ip [ip-address [secondary]]

no standby [group-number] ip [ip-address]

Syntax Description:


(Optional) Group number on the interface for which HSRP is being activated. Default is 0.


(Optional) IP address of the Hot Standby Router interface.


(Optional) Indicates the IP address is a secondary Hot Standby Router interface. Useful on interfaces with primary and secondary addresses; you can configure primary and secondary HSRP addresses.

Command Description:

To activate the Hot Standby Router Protocol (HSRP), use the standby ip interface configuration command. To disable HSRP, use the no form of this command.

The standby ip command activates HSRP on the configured interface. If an IP address is specified, that address is used as the designated address for the Hot Standby group. If no IP address is specified, the designated address is learned through the standby function. For HSRP to elect a designated router, at least one router on the cable must have been configured with, or learned, the designated address. Configuring the designated address on the active router always overrides a designated address that is currently in use.

When the standby ip command is enabled on an interface, the handling of proxy ARP requests is changed (unless proxy ARP was disabled). If the interface's Hot Standby state is active, proxy ARP requests are answered using the Hot Standby group's MAC address. If the interface is in a different state, proxy ARP responses are suppressed.

When group number 0 is used, no group number is written to NVRAM, providing backward compatibility.


The following example activates HSRP for group 1 on FastEthernet interface 0/0. The IP address used by the Hot Standby group will be learned using HSRP.

Router(config)#interface fastethernet 0/0
 Router(config-if)#standby 1 ip

In the following example, all three virtual IP addresses appear in the ARP table using the same (single) virtual MAC address. All three virtual IP addresses are using the same HSRP group (group 0).

Router(config-if)#ip address
Router(config-if)#ip address secondary
Router(config-if)#ip address secondary
Router(config-if)#ip address secondary
Router(config-if)#standby ip
Router(config-if)#standby ip secondary
Router(config-if)#standby ip secondary


Related commands:

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