Hello all, For 2 ou 3 weeks, all my DCs can't sync the time withmy PDC. These errors are logged on the DCs : Event Type: Information Event Source: W32Time Event Category: None Event ID: 38 Description: The time provider NtpClient can-t reach or receices invalid time datas from PDC (ntp.d|DC1:123->PDC:123). Event Type: Warning Event Source: W32Time Event Category: None Event ID: 24 Description: Time provider NtpClient: no valid response has been received from the domain controller PDC after 8 attempts. This domain controller will be rejected as time provider, and NtpClient will attempt to discover a new domain controller for synchronizing. Event Type: Error Event Source: W32Time Event Category: None Event ID: 29 Date: 11/16/2009 Time: 6:28:21 PM User: N/A Computer: PNTFLS02 Description: The time provider NtpClient is configured to acquire time from one or more time sources, however none of the sources are currently accessible. No attempt to contact a source will be made for 15 minutes. NtpClient has no source of accurate time. On PDC, I ran the command netstat -a on the PDC, and I didn't view anything about UDP 123. From DC1, I ran the command telnet PDC 123 and it solved by a connection failure. Thanks. Have a good day.FXE