Operation Manual – NTPH3C S5600 Series Ethernet Switches Chapter 1 NTP Configuration1-7Task RemarksDisplaying NTP Configuration Optional1.3 Configuring NTP Implementation ModesAn S5600 Ethernet switch can work in one of the following NTP modes:z Configuring NTP Server/Client Modez Configuring the NTP Symmetric Peer Modez Configuring NTP Broadcast Modez Configuring NTP Multicast ModeNote:To protect unused sockets against attacks by malicious users and improve security,H3C S5600 series Ethernet switches provide the following functions:z UDP port 123 is opened only when the NTP feature is enabled.z UDP port 123 is closed as the NTP feature is disabled.These functions are implemented as follows:z Execution of one of the ntp-service unicast-server, ntp-service unicast-peer,ntp-service broadcast-client, ntp-service broadcast-server, ntp-servicemulticast-client, and ntp-service multicast-server commands enables the NTPfeature and opens UDP port 123 at the same time.z Execution of the undo form of one of the above six commands disables allimplementation modes of the NTP feature and closes UDP port 123 at the sametime.1.3.1 Configuring NTP Server/Client ModeFor switches working in the server/client mode, you only need to perform configurationson the clients, and not on the servers.
