3Com 5500G-EI Command Reference Guide - Page 508

508 CHAPTER 12: USING SYSTEM MANAGEMENT COMMANDS Description Use the ntp-service multicast-client command to configure the NTP multicast client mode. Use the undo ntp-service multicast-client command to disable the NTP multicast client mode. By default, the multicast client service is disabled. ip-address defaults to 224.0.1.1. Designate an interface on the local Switch to receive NTP multicast messages and operate in multicast client mode. The local Switch listens to the multicast from the server. When it receives the first multicast packet, it starts a brief client/server mode to switch messages with a remote server for estimating the network delay. Thereafter, the local Switch enters multicast client mode and continues listening to the multicast and synchronizes the local clock according to the arrived multicast message. Example Configure to receive NTP multicast packet via Vlan-Interface1 and the multicast group corresponding to these packets located at 224.0.1.1. system-view System View: return to User View with Ctrl+Z. [SW5500]interface vlan-interface 1 [SW5500-Vlan-Interface1]ntp-service multicast-client 224.0.1.1 ntp-service multicast-server Syntax ntp-service multicast-server [ ip-address ] [ authentication-keyid keyid ] [ ttl ttl-number ] [ version number ]* undo ntp-service multicast-server [ ip-address ] View VLAN interface view Parameter ip-address: Specify a multicast IP address of Class D and default to 224.0.1.1. authentication-keyid: Specify authentication key. keyid: Key ID used in multicast, ranging from 1 to 4294967295. ttl: Define the time to live of a multicast packet. ttl-number: Specify the ttl of a multicast packet and range from 1 to 255. version: Define NTP version number. number: Specify NTP version number and range from 1 to 3. Description Use the ntp-service multicast-server command to configure NTP multicast server mode. Use the undo ntp-service multicast-server command to disable NTP multicast server mode. By default, the multicast service is disabled. IP address defaults to 224.0.1.1 and the version number defaults to 3.