TheNTP server command accepts server addresses in IPv4 or IPv6 format. When multiple NTP server addresses are in the list, the NTP server command sets the first obtainable address as the active NTP server. If there are no reachable time servers, then the local switch time is the default time.
The syntax to configure NTP server is:
VDX6740-1(config)# ntp server
ip-address is either IPv4 or IPv6 address
The command can be entered multiple times and both IPv4 and IPv6 addresses can be specified for the same VDX