# prefix

#### Syntax

prefix startIpv6Prefix { assignedPrefixLength | endIpv6Prefix } [ [ preferred | valid ] { days [ hours [ minutes [ seconds ] ] ] | infinite } ]

no prefix startIpv6Prefix [ force | preferred [ valid ] | valid ]

#### Release Information

Command introduced in JunosE Release 10.1.0.

#### Description

Specifies the prefix range from which IPv6 prefixes can be assigned to the DHCPv6 client. Also, configures the duration of time for which the requesting router can use the delegated prefix. If no value is specified for preferred or valid lifetime, the default lifetime of 1 day is used for the delegated prefix. The no version removes the IPv6 prefix range from the local address pool. You can also forcibly delete an IPv6 prefix range from which prefixes have been allocated.

| Note: If you attempt to configure a prefix range that overlaps with an existing prefix range in the same pool, an error message is displayed and the configuration fails. Also, an error message is displayed if you try to configure a prefix range that overlaps with a prefix range in another IPv6 local address pool on the same virtual router.

#### Options

- startIpv6Prefix—Starting IPv6 prefix of the range of prefixes to be delegated to requesting routers.
- endIpv6Prefix—Ending IPv6 prefix of the range of prefixes to be delegated to requesting routers.
- assignedPrefixLength—Length of the IPv6 prefix to be assigned from this range of prefixes to the requesting router.
- preferred—Specifies use of the preferred period of time for the requesting router to use the prefix delegated by the DHCPv6 server. If the preferred lifetime is not specified, the prefix can be used by the requesting router for the default period of 1 day.
- valid—Specifies use of the valid period of time for the requesting router to use the prefix delegated by the DHCPv6 server. If the valid lifetime is not specified, the prefix can be used by the requesting router for the default period of 1 day.

  | Note: Although you can configure the valid lifetime for a prefix, the DHCPv6 server does not consider this value. The DHCPv6 server uses only the preferred lifetime for a prefix to determine the amount of time for which a prefix can be used by the requesting router.

- days—Number of days for the preferred or valid lifetime; in the range 0-32768.
- hours—Number of hours for the preferred or valid lifetime; in the range 0-24.
- minutes—Number of minutes for the preferred or valid lifetime; in the range 0-60.
- seconds—Number of seconds for the preferred or valid lifetime; in the range 0-60.
- infinite—Assigns a preferred or valid lifetime that does not expire for the delegated prefix.
- force—Forcibly deletes the IPv6 prefix range from the local address pool.

#### Mode

IPv6 Local Pool Configuration