Ntpdate and ntpd failing to sync clock on Linux. At first I thought maybe a local or network firewall was blocking UDP port 123, but that is not the case- this server can talk UDP port 123 (the ntp protocol) to the Internet and get answers. Let me demonstrate the issue.
I am going to do a time sync for my server.
Tried portqry to the time server with below results:
C:PortQryV2>portqry -n 'time server' -e 123 -p both
Querying target system called:
'time server'
Attempting to resolve IP address to a name...
Failed to resolve IP address to name
querying...
TCP port 123 (unknown service): NOT LISTENING
UDP port 123 (ntp service): LISTENING or FILTERED
UDP port 123 (ntp service): LISTENING or FILTERED
I am not sure if the port is available for time sync or not.But our team has confirmed that no firewall should be blocking that.
It is not showing 'LISTENING' because it is a UDP port?
S. HungS. Hung
2 Answers
LISTENING or FILTERED simply means Portqry does not get a response from the port specified.The problem should be at
Failed to resolve IP address to name
resolve the hostname and try again.
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I tried on a PC which is not going to do the time syn. It can resolve the hostname but got the same result for UDP query:
C:PortQryV2>portqry -n 'IP Address' -e 123 -p both
Querying target system called:
'IP Address'
Attempting to resolve IP address to a name...
IP address resolved to xxx.corp.com
querying...
TCP port 123 (unknown service): NOT LISTENING
UDP port 123 (ntp service): LISTENING or FILTERED
S. HungS. Hung