Operation Manual – NTPH3C S7500 Series Ethernet Switches Chapter 1 NTP Configuration1-8Note:z The total number of the servers and peers configured for a switch can be up to 128.z After the configuration, the S7500 series switch does not establish connections withthe peer if it operates in NTP server mode. Whereas if it operates in any of the othermodes, it establishes connections with the peer.z If an S7500 series switch operates as a passive peer in peer mode, NTP broadcastclient mode, or NTP multicast client mode, the connections it establishes with thepeers are dynamic. If it operates in other modes, the connections it establishes withthe peers are static.1.3 Access Control Permission ConfigurationAccess control permission to NTP server is a security measure that is of the minimumextent. Authentication is more reliable comparing to it.An access request made to an NTP server is matched from the highest permission tothe lowest, that is, in the order of peer, server, synchronization, and query.Follow these steps to configure the access control permission to the local NTP server:To do... Use the command... RemarksEnter system view system-view —Configure the accesscontrol permission to thelocal NTP serverntp-service access{ peer | server |synchronization |query } acl-numberOptionalBy default, the accesscontrol permission to thelocal NTP server is peer1.4 NTP Authentication ConfigurationFor the networks with higher security requirements, you can specify to performauthentications when enabling NTP. With the authentications performed on both theclient side and the server side, the client is synchronized only to the server that passesthe authentication. This improves network security.1.4.1 PrerequisitesNTP authentication configuration involves:z Configuring NTP authentication on the clientz Configuring NTP authentication on the serverNote the following when performing NTP authentication configuration:
