HP 6120XG ProCurve Series 6120 Blade Switches Management and Configuration Gui - Page 191

Time Protocols Overview Notes 9-2 Overview This chapter describes: ■ SNTP Time Protocol Operation ■ Timep Time Protocol Operation Using time synchronization ensures a uniform time among interoperating devices. This helps you to manage and troubleshoot switch operation by attaching meaningful time data to event and error messages. The switch offers TimeP and SNTP (Simple Network Time Protocol) and a timesync command for changing the time protocol selection (or turning off time protocol operation). ■ Although you can create and save configurations for both time protocols without conflicts, the switch allows only one active time protocol at any time. ■ In the factory-default configuration, the time synchronization option is set to TimeP, with the TimeP mode itself set to Disabled. TimeP Time Synchronization You can either manually assign the switch to use a TimeP server or use DHCP to assign the TimeP server. In either case, the switch can get its time synchronization updates from only one, designated Timep server. This option enhances security by specifying which time server to use. SNTP Time Synchronization SNTP provides two operating modes: ■ Broadcast Mode: The switch acquires time updates by accepting the time value from the first SNTP time broadcast detected. (In this case, the SNTP server must be configured to broadcast time updates to the network broadcast address. Refer to the documentation provided with your SNTP server application.) Once the switch detects a particular server, it ignores time broadcasts from other SNTP servers unless the configurable Poll Interval expires three consecutive times without an update received from the first-detected server.