Configure Cisco router as an NTP server

An NTP server can provide synchronized date and times for devices in a network. Since a router cannot be a Stratum 1 device (cannot connect to a Stratum 0 device such as a GPS clock), a router is not an accurate source of time information. If this is not important to you, then using a router as an NTP server may be acceptable.

To configure the router to work as an NTP server, use the following command in configuration mode (following a conf t):

ntp master 8

The 8 specifies the stratum of this NTP server, essentially the number of hops away from a Stratum 0 device. The default value is 8.

courtesy http://www.tech-recipes.com/rx/1464/configure_cisco_router_ntp_server/