Configuring The Neighbor Solicitation Message Interval; Configuring The Neighbor Reachable Time - Cisco ASA 5505 Configuration Manual

Chapter 7 Using the Startup Wizard
Neighbor solicitation messages are also used to verify the reachability of a neighbor after the link-layer
address of a neighbor is identified. When a node wants to verify the reachability of a neighbor, the
destination address in a neighbor solicitation message is the unicast address of the neighbor.
Neighbor advertisement messages are also sent when there is a change in the link-layer address of a node
on a local link. When there is such a change, the destination address for the neighbor advertisement is
the all-nodes multicast address.
You can configure the neighbor solicitation message interval and neighbor reachable time on a
per-interface basis.
In addition, you can configure DAD settings, IPv6 addresses, and IPv6 prefixes. For more information,
see the following sections:
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Configuring the Neighbor Solicitation Message Interval

You can configure the interval between IPv6 neighbor solicitation retransmissions on an interface. Valid
values range from 1000 to 3600000 milliseconds. The default value is 1000 milliseconds. This setting is
also sent in router advertisement messages.
To configure the neighbor solicitation message interval, perform the following steps:
Choose Configuration > Device Setup > Interfaces.
Step 1
Step 2 Choose the interface on which to configure the neighbor solicitation interval. The interface must have
been configured with an IPv6 address. See the
page 7-18
Click Edit. The Edit Interface dialog box appears with three tabs: General, Advanced, and IPv6.
Step 3
Click the IPv6 tab.
Step 4
In the NS Interval field, enter the time interval.
Step 5
Click OK.
Step 6
Step 7 Click Apply to save the configuration.

Configuring the Neighbor Reachable Time

The neighbor reachable time enables detecting unavailable neighbors. Shorter configured times enable
detecting unavailable neighbors more quickly; however, shorter times consume more IPv6 network
bandwidth and processing resources in all IPv6 network devices. Very short configured times are not
recommended in normal IPv6 operation.
Valid time values range from 0 to 3600000 milliseconds. The default is 0; however, when you use 0, the
reachable time is sent as undetermined. It is up to the receiving devices to set and track the reachable
time value.
OL-20339-01
Configuring the Neighbor Solicitation Message Interval, page 7-19
Configuring the Neighbor Reachable Time, page 7-19
Configuring DAD Settings, page 7-20
Configuring IPv6 Addresses on an Interface, page 7-21
Configuring IPv6 Prefixes on an Interface, page 7-21
for more information.
Configuring IPv6 Neighbor Discovery
"Configuring IPv6 Neighbor Discovery" section on
Cisco ASA 5500 Series Configuration Guide using ASDM
7-19