CLI Reference Guide-R07

Chapter 27 | IP Interface Commands
IPv6 Interface
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ipv6 nd
reachable-time
This command configures the amount of time that a remote IPv6 node is
considered reachable after some reachability confirmation event has occurred. Use
the no form to restore the default setting.
Syntax
ipv6 nd reachable-time milliseconds
no ipv6 nd reachable-time
milliseconds - The time that a node can be considered reachable after
receiving confirmation of reachability. (Range: 0-3600000)
Default Setting
30000 milliseconds is used for neighbor discovery operations
Command Mode
Interface Configuration (VLAN)
Command Usage
◆ The time limit configured by this parameter allows the router to detect
unavailable neighbors. During the neighbor discover process, an IPv6 node will
multicast neighbor solicitation messages to search for neighbor nodes. For a
neighbor node to be considered reachable, it must respond to the neighbor
soliciting node with a neighbor advertisement message to become a
confirmed neighbor, after which the reachable timer will be considered in
effect for subsequent unicast IPv6 layer communications.
Example
The following sets the reachable time for a remote node to 1000 milliseconds:
Console(config)#interface vlan 1
Console(config)#ipv6 nd reachable-time 1000
Console(config)#
clear ipv6 neighbors This command deletes all dynamic entries in the IPv6 neighbor discovery cache.
Command Mode
Privileged Exec
Example
The following deletes all dynamic entries in the IPv6 neighbor cache:
Console#clear ipv6 neighbors
Console#