.It Xo Ic interface

.Oo

.Cm listen |

.Cm ignore |

.Cm drop

.Oc

.Oo

.Cm all |

.Cm ipv4 | 

.Cm ipv6 | 

.Cm wildcard | 

.Cm name | 

.Cm address \&/prefixlen

.Oc

.Xc

This command controls which network addresses ntpd opens, and whether input is

dropped without processing. The first parameter determines the action for

addresses which match the second parameter. That parameter specifies a class

of addresses, or a specific interface name, or an address. In the address

case, prefixlen determines how many bits must match for this rule to apply.

ignore prevents opening matching addresses, drop causes ntpd to open the

address and drop all received packets without examination. Multiple interface

commands can be used. The last rule which matches a particular address

determines the action for it. interface commands are disabled if any 

.Cm -I ,

.Cm --interface , 

.Cm -L , 

or 

.Cm --novirtualips 

command-line options are used. If none of those options are used and no 

interface actions are specified in the configuration file, all available 

network addresses are opened. The nic command is an alias for interface.