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Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter28 Configuring IPv6 Neighbor Discovery
Configuring the IPv6 Prefix
Configuring the IPv6 Prefix
To configure the which IPv6 prefixes are included in IPv6 router advertisements, enter the following
command:
Command Purpose
ipv6 nd prefix ipv6-prefix/prefix-length |
default [[valid-lifetime
preferred-lifetime] | [at valid-date
preferred-date] | infinite | no-advertise
| off-link | no-autoconfig]
Example:
hostname (config-if)# ipv6 nd prefix
2001:DB8::/32 1000 900
Configures which IPv6 prefixes are included in IPv6 router advertisements.
The prefix advertisement can be used by neighboring devices to
autoconfigure their interface addresses. Stateless autoconfiguration uses
IPv6 prefixes provided in router advertisement messages to create the
global unicast address from the link-local address.
The at valid-date preferred-date syntax indicates the date and time at
which the lifetime and preference expire. The prefix is valid until this
specified date and time are reached. Dates are expressed in the form
date-valid-expire month-valid-expire hh:mm-valid-expire
date-prefer-expire month-prefer-expire hh:mm-prefer-expire.
The default keyword indicates that default values are used.
The optional infinite keyword specifies that the valid lifetime does not
expire.
The ipv6-prefix argument specifies the IPv6 network number to include in
router advertisements. This argument must be in the form documented in
RFC 2373 where the address is specified in hexadecimal using 16-bit
values between colons.
The optional no-advertise keyword indicates to hosts on the local link that
the specified prefix is not to be used for IPv6 autoconfiguration.
The optional no-autoconfig keyword indicates to hosts on the local link
that the specified prefix cannot be used for IPv6 autoconfiguration.
The optional off-link keyword indicates that the specified prefix is not used
for on-link determination.
The preferred-lifetime argument specifies the amount of time (in seconds)
that the specified IPv6 prefix is advertised as being preferred. Valid values
range from 0 to 4294967295 seconds. The maximum value represents
infinity, which can also be specified with infinite. The default is 604800 (7
days).
The prefix-length argument specifies the length of the IPv6 prefix. This
value indicates how many of the high-order, contiguous bits of the address
comprise the network portion of the prefix. The slash (/) must precede the
prefix length.
The valid-lifetime argument specifies the amount of time that the specified
IPv6 prefix is advertised as being valid. Valid values range from 0 to
4294967295 seconds. The maximum value represents infinity, which can
also be specified with infinite. The default is 2592000 (30 days).