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Command Line Interface
4-324
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standby authentication
This command specifies the key used to authenticate HSRP packets received from
other routers. Use the no form to delete an authentication string.
Syntax
standby [group] authentication string
no standby [group] authentication
• group - Identifies the HSRP group. (Range: 0-255)
• string - Authentication string. (Range: 1-8 alphanumeric characters)
Default Setting
Group number: 0
String: not defined
Command Mode
Interface (VLAN)
Command Usage
• All routers in the same HSRP group must be configured with the same
authentication string. The authentication string is sent unencrypted in all
HSRP messages.
• When an HSRP packet is received from another router in the group, its
authentication string is compared to the string configured on this router. If the
strings match, the message is accepted. Otherwise, the packet is discarded.
If the authentication strings do not match, this router will not be able to learn
the designated address for the group and timer values from other routers.
However, even if authentication fails, this cannot prevent a router from taking
over as the master router if it has the highest priority in the group.
• Priority takes precedence over authentication. In other words, if a router is
configured with the standby priority command to have the highest priority in
the group, but does not have an authentication string, or is configured with the
wrong string, it will still take over as the active master.
Example
Related Commands
standby priority (4-322)
Console(config-if)#standby 1 authentication bluebird
Console(config-if)#