NTP Server - Revision history

Craigje: /* Explanation */

2015-05-20T12:46:05Z

Explanation

← Older revision		Revision as of 12:46, 20 May 2015
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	=Explanation=		=Explanation=
			Our Earthmate GPS, in position outside

			[[File:GpsPic.jpg]]

	==Setup Procedure (Serverside)==		==Setup Procedure (Serverside)==
	Plug the GPS device into proto via USB.		Plug the GPS device into proto via USB.

Craigje: /* Troubleshooting */

2015-05-19T18:33:20Z

Troubleshooting

← Older revision		Revision as of 18:33, 19 May 2015
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	==Troubleshooting==		==Troubleshooting==
	~~Currently the~~ GPS ~~is the~~ gray ~~cable running from Proto's front usb~~-~~port to the PVC pipe that runs outside.~~		GPS attached via USB connection:
			*GPS -> black USB -> gray USB -> proto

	The daemon is located at "/etc/init.d/ntp status".		The daemon is located at "/etc/init.d/ntp status".

Craigje at 18:14, 19 May 2015

2015-05-19T18:14:46Z

← Older revision		Revision as of 18:14, 19 May 2015
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	proto.cs.earlham.edu is an ntp timeserver for Earlham's network. The time value it outputs come from some weighted average of two inputs. The first input is a NIST server located in Chicago. The second input is a GPS device on ~~the fourth floor of dennis~~ (in a box connected to the 4th floor lab's closet).		proto.cs.earlham.edu is an ntp timeserver for Earlham's network. The time value it outputs come from some weighted average of two inputs. The first input is a NIST server located in Chicago. The second input is a GPS device on Dennis roof (in the electric-style box connected to the 4th floor lab closet).

	=Explanation=		=Explanation=

Akseewa11: /* The Server-Side Configuration File on Proto */

2014-09-01T19:09:38Z

The Server-Side Configuration File on Proto

← Older revision		Revision as of 19:09, 1 September 2014
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	#Allows all users on the Earlham network, characterized by IPv4 address		#Allows all users on the Earlham network, characterized by IPv4 address
	#starting with 159.28, to synchronize.		#starting with 159.28, to synchronize.
	restrict default ~~kod nomodify notrap~~		restrict default ignore
	restrict 159.28.0.0 mask 255.255.0.0 nomodify notrap		restrict 159.28.0.0 mask 255.255.0.0 nomodify notrap

Ghcrows13: /* Clients */

2014-06-26T11:17:30Z

Clients

← Older revision		Revision as of 11:17, 26 June 2014
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	ACLs		ACLs

	clusters?		clusters?

Ghcrows13 at 11:17, 26 June 2014

2014-06-26T11:17:17Z

← Older revision		Revision as of 11:17, 26 June 2014
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	==Clients==		==Clients==
			Only the 159.28.0.0 subnet can access Proto's NTP.

	ACLs		ACLs
	clusters?		clusters?

Ghcrows13 at 11:13, 26 June 2014

2014-06-26T11:13:10Z

← Older revision		Revision as of 11:13, 26 June 2014
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	==Troubleshooting==		==Troubleshooting==
	~~The~~ GPS is the gray cable running from Proto's front usb-port to the PVC pipe that runs outside.		Currently the GPS is the gray cable running from Proto's front usb-port to the PVC pipe that runs outside.

	NTP logs are located at /var/log/daemon.log ~~and are useful for diagnosing issues~~. In one circumstance the gps0 device was reporting that it wasn't found. It turned out that ttyUSB0 (the GPS) wasn't recognized despite it being plugged in. I unplugged and replugged the GPS. It worked.		The daemon is located at "/etc/init.d/ntp status".

			NTP logs are located at "/var/log/daemon.log". In one circumstance the gps0 device was reporting that it wasn't found. It turned out that ttyUSB0 (the GPS) wasn't recognized despite it being plugged in. I unplugged and replugged the GPS. It worked.

			To check if NTP is functioning correctly execute "ntpq -p" on clients or "ntpq -p proto.cs.earlham.edu" from within the CS subnet. The "when" field should be less than the "poll" field.

			==Clients==
			ACLs
			clusters?

	==The Server-Side Configuration File on Proto==		==The Server-Side Configuration File on Proto==

Ghcrows13 at 11:04, 26 June 2014

2014-06-26T11:04:56Z

← Older revision		Revision as of 11:04, 26 June 2014
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	==Explanation of Choices==		==Explanation of Choices==
	Since it is easy to configure one's time to a NIST timeserver and NIST uses highly accurate atomic clocks, you might wonder why we bother with the GPS. The locality of the GPS reduces network latency and network jitter as sources of error. While, for Earlham, the GPS signal may be more accurate, it is also less reliable. Somebody might accidentally unplug the GPS and HIP might not notice for a few hours/days, whereas the NIST server's importance means that attentive, skillful people would notice problems sooner. Considering this worst case scenario, and the fact that the different between 3:17:30 and 3:17:20 100% of the time is less important to most people than the difference between 4:17:30 and 3:17:30 0.28 percent of the time, it is best to mix the inputs		Since it is easy to configure one's time to a NIST timeserver and NIST uses highly accurate atomic clocks, you might wonder why we bother with the GPS. The locality of the GPS reduces network latency and network jitter as sources of error. While, for Earlham, the GPS signal may be more accurate, it is also less reliable. Somebody might accidentally unplug the GPS and HIP might not notice for a few hours/days, whereas the NIST server's importance means that attentive, skillful people would notice problems sooner. Considering this worst case scenario, and the fact that the different between 3:17:30 and 3:17:20 100% of the time is less important to most people than the difference between 4:17:30 and 3:17:30 0.28 percent of the time, it is best to mix the inputs

			==Troubleshooting==
			The GPS is the gray cable running from Proto's front usb-port to the PVC pipe that runs outside.

			NTP logs are located at /var/log/daemon.log and are useful for diagnosing issues. In one circumstance the gps0 device was reporting that it wasn't found. It turned out that ttyUSB0 (the GPS) wasn't recognized despite it being plugged in. I unplugged and replugged the GPS. It worked.

	==The Server-Side Configuration File on Proto==		==The Server-Side Configuration File on Proto==

Ghcrows13 at 10:51, 26 June 2014

2014-06-26T10:51:39Z

← Older revision		Revision as of 10:51, 26 June 2014
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	proto.cs.earlham.edu is an ntp timeserver for Earlham's network. The time value it outputs come from some weighted average of two inputs. The first input is a NIST server located in Chicago. The second input is a GPS device on the fourth floor of dennis (in a box connected to the 4th floor lab's closet).		proto.cs.earlham.edu is an ntp timeserver for Earlham's network. The time value it outputs come from some weighted average of two inputs. The first input is a NIST server located in Chicago. The second input is a GPS device on the fourth floor of dennis (in a box connected to the 4th floor lab's closet).

	=~~menu~~=		=Explanation=
	==Setup Procedure (Serverside)==		==Setup Procedure (Serverside)==
	Plug the GPS device into proto via USB.		Plug the GPS device into proto via USB.
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	The fudge line is also optional, but its effect of notifying ntp's algorithms of proto's stratum 1 quality is beneficial.		The fudge line is also optional, but its effect of notifying ntp's algorithms of proto's stratum 1 quality is beneficial.

	~~<p align~~=~~"center"> '''~~Managing the Client's NTP daemon~~''' </p>~~		==Managing the Client's NTP daemon==
	The "/etc/init.d/ntpd" command controls the ntp daemon. Passing it one of the parameters {restart, stop, start}, e.g. "/etc/init.d/ntpd restart" does exactly what you might imagine. After editing the configuration file to include proto as a server, you will need to restart the daemon for the changes to take effect.		The "/etc/init.d/ntpd" command controls the ntp daemon. Passing it one of the parameters {restart, stop, start}, e.g. "/etc/init.d/ntpd restart" does exactly what you might imagine. After editing the configuration file to include proto as a server, you will need to restart the daemon for the changes to take effect.

	~~<p align~~=~~"center"> '''~~Testing and Debugging~~''' </p>~~		==Testing and Debugging==
	Type 'ntpdc' into your shell. That should give you an interpreter to which you will give the command 'peers'. If there is the value "=proto.cs.earlham.edu" in the first column of the output, then you are getting your time from proto.		Type 'ntpdc' into your shell. That should give you an interpreter to which you will give the command 'peers'. If there is the value "=proto.cs.earlham.edu" in the first column of the output, then you are getting your time from proto.

	~~<p align~~=~~"center"> '''~~Explanation of Choices~~''' </p>~~		==Explanation of Choices==
	Since it is easy to configure one's time to a NIST timeserver and NIST uses highly accurate atomic clocks, you might wonder why we bother with the GPS. The locality of the GPS reduces network latency and network jitter as sources of error. While, for Earlham, the GPS signal may be more accurate, it is also less reliable. Somebody might accidentally unplug the GPS and HIP might not notice for a few hours/days, whereas the NIST server's importance means that attentive, skillful people would notice problems sooner. Considering this worst case scenario, and the fact that the different between 3:17:30 and 3:17:20 100% of the time is less important to most people than the difference between 4:17:30 and 3:17:30 0.28 percent of the time, it is best to mix the inputs		Since it is easy to configure one's time to a NIST timeserver and NIST uses highly accurate atomic clocks, you might wonder why we bother with the GPS. The locality of the GPS reduces network latency and network jitter as sources of error. While, for Earlham, the GPS signal may be more accurate, it is also less reliable. Somebody might accidentally unplug the GPS and HIP might not notice for a few hours/days, whereas the NIST server's importance means that attentive, skillful people would notice problems sooner. Considering this worst case scenario, and the fact that the different between 3:17:30 and 3:17:20 100% of the time is less important to most people than the difference between 4:17:30 and 3:17:30 0.28 percent of the time, it is best to mix the inputs

Ghcrows13 at 10:50, 26 June 2014

2014-06-26T10:50:36Z

← Older revision		Revision as of 10:50, 26 June 2014
Line 1:		Line 1:
	proto.cs.earlham.edu is an ntp timeserver for Earlham's network. The time value it outputs come from some weighted average of two inputs. The first input is a NIST server located in Chicago. The second input is a GPS device on the fourth floor of dennis (in a box connected to the 4th floor lab's closet).		proto.cs.earlham.edu is an ntp timeserver for Earlham's network. The time value it outputs come from some weighted average of two inputs. The first input is a NIST server located in Chicago. The second input is a GPS device on the fourth floor of dennis (in a box connected to the 4th floor lab's closet).

			=menu=
	==Setup Procedure (Serverside)==		==Setup Procedure (Serverside)==
	Plug the GPS device into proto via USB.		Plug the GPS device into proto via USB.