Solve ntp error noserversuitableforsynchronizationfound

Resolving ntp errors noserversuitableforsynchronizationfound when ntpdate-d is used for query, there are two errors that cause noserversuitableforsynchronizationfound: error 1 Serverdropp ntp solution error no server suitable for synchronization found when ntpdate-d is used for query, there are two error messages that cause no server suitable for synchronization found: error 1. server dropped: Strata too high runs ntpdate serverIP on the ntp client, and the error "no server suitable for synchronization found" appears. On the ntp client, use ntpdate-d serverIP to view the error "Server dropped: strata too high" and display "stratum 16 ". Normally, the value range of stratum is "0 ~ 15 ". This is because the NTP server is not synchronized with itself or its server. The following definition is to keep the NTP Server synchronized with itself. if the server defined in/ntp. conf is unavailable, the local time will be used as the ntp service and provided to the ntp client. After server 127.127.1.0fudge 127.127.1.0 stratum 8 restarts the ntp service on the ntp server, it may take five minutes to synchronize the ntp server itself or its server, during this time, when the client runs the ntpdate command, the no server suitable for synchronization found error is generated. So how do I know when the ntp server completes the synchronization process with itself? Run the following command on the ntp server: # watch ntpq-p: Every 2.0 s: ntpq-p Thu Jul 10 02:28:32 2008 remote refid st t when poll reach delay offset jitter ============== ========================================================== ==================== 192.168.30.22 LOCAL (0) 8 u 22 64 1 2.113 179133. 0.001 LOCAL (0) LOCAL (0) 10 l 21 64 1 0.000 0.000 0.001 note that LOCAL is the ntp server synchronized with itself. Note that the value of reach increases from 0 after the ntp server service is started. when the value is increased to 17, it is changed 5 times from 0 to 17, the number of seconds for each poll value, which is the time for 64 seconds * 5 = 320 seconds. If the ntp server synchronization from the ntp client still fails, use ntpdate-d to query the detailed error information and make a judgment. Error 2. server dropped: no data when the client executes netdate-d, the error message is as follows: transmit (192.168.30.22) transmit (192.168.30.22) transmit (192.168.30.22) transmit (192.168.30.22) transmit (192.168.30.22) 192.168.30.22: server dropped: no data server 192.168.30.22, port 123 ..... 28 Jul 17:42:24 ntpdate [14148]: no server suitable for synchronization found may be caused by 2: 1. Check the ntp version. if you use a version later than ntp4.2 (including 4.2) and use notrust in the restrict definition, the above error will occur. Run The following command to check The ntp version: # ntpq-c version The following is a description from The ntp official website: The behavior of notrust changed between versions 4.1 and 4.2. in 4.1 (and earlier) notrust meant "Don't trust this host/subnet for time ". in 4.2 (and later) notrust means "Ignore all NTP packets that are not cryptographically authenticated. "This forces remote time servers to authenticate themselves to your (client) ntpd solution: remove notrust. 2. Check the ntp server firewall. It may be that the server's firewall shields upd Port 123. You can use the command # service iptables stop to disable the iptables service and try to synchronize data from the ntp client. if it succeeds, it turns out that it is a firewall problem and you need to change the iptables settings.