Juniper JUNOSE 11.1.X - COMMAND REFERENCE N TO Z 4-6-2010 Command Reference Manual page 303

Chapter 4: P Commands
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.
IPv6 Local Pool Configuration
Mode
261
prefix