Archive for the ‘NTP configuration’ Category
Accurate time is one of the most important aspects to keeping a computer network secure and safe. Places such as stock exchanges, banks and air traffic control rely on secure and accurate time. As computers rely on time as their only reference for when events happen, a slight error in a time code could lead to all sorts of errors, from millions being wiped off share prices to aeroplane flight paths being incorrect.
And time doesn’t just need to be accurate for these organizations, but secure too. A malicious user who interferes with a timestamp could cause all sorts of trouble, so ensuring time sources are both secure and accurate is vital.
Security is increasingly important for all sorts of organisations. With so much trade and communication conducted over the internet, using a source of accurate and secure time is as important a part of network security as anti-virus and firewall protection.
Despite the need for accuracy and security, many computer networks still rely on online time servers. Internet sources of time are not only unreliable, with inaccuracies commonplace, and distance and latency affecting the precision, but an Internet time server is also unsecure and able to be hijacked by malicious users.
But an accurate, reliable and completely secure source of time is available everywhere, 365 days a year—GPS.
While commonly thought of as a means of navigation, GPS actually provides an atomic clock time code, direct from the satellite signals. It is this time code that navigation systems use for calculating position but it is just as effective to provide a secure time stamp for a computer network.
Organizations that rely on accurate time for safety and security all use GPS, as it is a continuous signal, that never goes down, is always accurate and can’t be interfered with by third parties.
To utilise GPS as a source of time, all that is required is a GPS time server. Using an antenna, the time server receives the GPS signal, while NTP (Network Time Protocol) distributes it around the network.
With a GPS time server, a computer network is able to maintain accuracy to within a few milliseconds of the atomic clock time signal, which is translated into UTC time (Coordinated Universal Time) thanks to NTP, ensuring the network is running the same accurate time as other networks also synchronised to a UTC time source.
Atomic clock and NTP server specialists, Galleon Systems, have relaunched their website providing an improved platform to showcase their wide range of time synchronisation and network time server products.
Galleon Systems, who have been providing atomic clock and time server products to industry and commerce for over a decade, have redesigned their website to ensure the company continues to be world leaders in providing accurate, secure and reliable time synchronisation products.
With detailed descriptions of their product range, new product pictures and a revamped menu system to provided better functionality and user experience, the new website includes all of Galleons extensive range of NTP server systems (Network Time Protocol) and atomic clock synchronisation products.
Time servers from Galleon Systems are accurate to within a fraction of a second and are a secure and reliable method of getting a source of atomic clock time for computer networks and technological applications.
Using either GPS or the UKs MSF radio signal (DSF in Europe WWVB in the USA), time servers from Galleon Systems can keep hundreds of devices on a network accurate to within a few milliseconds of the international timescale UTC (Coordinated Universal Time).
Galleon Systems product range includes a variety of NTP time servers that can receive either GPS or radio referenced signals, dual systems that can receive both, simple radio controlled atomic clock servers, and a range of large network digital and analogue wall clocks.
Manufactured in the UK, Galleon Systems have a wide range of NTP and time synchronisation devices used worldwide by thousands of organizations who need accurate, reliable and precise time. For more information please visit their new website: www.galsys.co.uk
In a global economy time has become a more crucial than ever before. As people across the globe, communicate, conference and buy and sell from each other, being aware of the each other’s time is vital for conducting business successfully.
And with the internet, global communication and time awareness are even more important as computers require a source of time for nearly all their applications and processes. The difficulty with computer communication, however, is that if different machines are running different times, all sorts of errors can occur. Data can get lost, errors fail to log; the system can become unsecure, unstable and unreliable.
Time synchronisation for computer networks communicating with each other is, therefore, essential – but how is it achieved when different networks are in different time-zones?
The answer lies with Universal Coordinated Time (UTC) an international time-zones developed in the 1970’2 that is based on accurate atomic clocks. UTC is set the same the world over, with no accounting for time-zones so the time on a network in the UK – will be identical to the network time in the USA.
UTC time on a computer network is also kept synchronised through the use of NTP (Network Time Protocol) and an NTP server. NTP ensures all devices on a networked system have exactly the right time as different computer clocks will drift at varying rates – even if the machines are identical.
While UTC makes no accounting for time-zones system clocks can still be set to the local time-zone but the applications and functions of a computer will use UTC.
UTC time is delivered to computer networks through a variety of sources: radio signals, the GPS signal, or across the internet (although the accuracy of internet time is debatable). Most computer networks have a NTP time server somewhere in their server room which will receive the time signal and distribute it through the network ensuring all machines are within a few milliseconds of UTC and that the time on your network corresponds to every other UTC network on the globe.
When it comes to time synchronisation and using Network Time Protocol (NTP) to ensure accuracy on a computer network, it is important to understand the hierarchy of NTP and how it affects distance and accuracy.
NTP has a hierarchical structure known as stratum levels. In principle the lower the stratum number the closer the device is (in accuracy terms) to an original time source.
NTP time servers work by receiving a single time source and using this as a basis for all time on the network, however, a synchronised network will be only as accurate as the original time source and this is where stratum levels come in.
And atomic clock, either one sat in a large scale physics laboratory, or those aboard GPS satellites, are stratum 0 devices. In other words these are the devices that actually generate the time.
Stratum 1 devices are NTP time servers that get their source of time directly from these stratum 0 atomic clocks. Either by using a GPS receiver or a radio referenced NTP server, a stratum 1 device is as accurate as you can get without having your own multi-million dollar atomic clock in the server room. A stratum 1 NTP time server will typically be accurate to within a millisecond of the atomic clock time.
Stratum 2 devices are the next step down on stratum level chain. These are time servers that receive their time from a stratum 1 device. Most online time servers, for instance, are stratum 2 devices, getting their time from another NTP time server. Stratum 2 devices are obviously further away from the original time source and therefore are not quite as accurate.
The stratum levels on an NTP network continue on, with devices connecting to devices going all the way down to stratum 10, 11, 12 and so on – obviously the more links in the chain the less accurate the device will be.
Dedicated stratum 1 NTP time servers are by far the most accurate, reliable and secure method of synchronising a computer network and no business network should really be without one.
As half the world is engrossed in the four yearly football tournament, it is a good opportunity to highlight the importance of accurate time and how it enables the entire world to watch events such as the Fifa World Cup.
Many of us have been glued to the love football coverage that is being broadcast by a multitude of different broadcasters and TV companies to nearly all countries across the globe.
But nearly all the technologies that enable this mass global live transmission: from the communication satellites that beam the signal across the globe, to the receivers that distribute them to our dishes, cable boxes and aerials.
And with online broadcasting now part and parcel of the whole live sporting event package – accurate time is even more important.
With signals being bounced from football stadiums to satellites and then to our homes, it is essential that all the technologies involved are synchronised as accurately as possible. Failure to do so could cause the signals to get lost, create interferences or cause a qhole host of other problems.
Most technologies rely on time servers to ensure accuracy and synchronisation. Most time synchronisation servers use the protocol NTP (Network Time Protocol) to distribute time across technology networks.
These devices use a single time source, often acquired from an external atomic clock that is used to set all system clocks on devices to.
Most modern computer networks have a NTP time server that controls the time. These devices are simple to set up and in a modern, global world, are a must have for anybody conscious about accuracy and security (Many security and malicious network attacks are caused due to a lack of synchronisation).
A single NTP time server can keep a network of hundreds and even thousands of machines accurate to within a few milliseconds to the world’s global timescale UTC (Coordinated Universal Time).
Time synchronisation is a critical aspect to modern computing, especially when computers are on a network or need to communicate with other networked machines.
Timestamps are crucial for computers to acknowledge when an event occurred and it is the only information they have to ascertain if an event has occurred. Without accurate time stamps the consequences can include:
• Loss of data
• Difficult to log errors
• Difficult to debug
• Failure to save
• Time sensitive applications may fail
Modern operating systems like Windows 7 have automatic synchronisation software already installed. W32Time has been a part of Microsoft’s different generations of operating systems for some time but in Windows 7 it is set to be automatically on (Rather than the user having to set it) – synchronising your PC straight out of the box.
With such NTP (Network Time Protocol) based synchronisation available by using internet time servers (normally Microsoft and NIST) many people may wonder if a dedicated time server is still required.
Problems with Internet Time Servers
There are several drawbacks to using this Internet time as a source of UTC (Coordinated Universal Time – the global timescale often referred to as GMT).
The first and most important drawback to internet time servers is their location through the firewall. Having to rely on a source of time across the internet means keeping the TCP port open – a crucial security weakness that can be used by malicious users or bots.
Another downside to internet time servers is their lack of guaranteed accuracy. While places like NIST (National Institute for Standards and Time) and Microsoft have reliable and accurate time servers – the accuracy can be dependent on how far away you are peering from. And many other time servers available as a source of internet time are less reliable – and as NTP can’t authenticate a time signal from across the internet – it can be difficult to assess.
Benefits of an External NTP Server
Dedicated external NTP servers are far more secure. They receive their tie from GPS satellites of Long Wave transmissions so the signals can’t be intercepted by computer hackers or malicious software. Also, NTP can authenticate the signals ensuring you know where they are coming from and how accurate they are.
With time being so important on modern networked computers, taking a risk with internet time may cost a lot more than any minor investment in a dedicated NTP time server.
Accurate time is so important for modern computer systems that it is now unimaginable for any network administer to configure a computer system without any regard to synchronisation.
Ensuring all machines are running an accurate and precise time, and that the entire network is synchronised together, will prevent problems arising such as data loss, failure of time sensitive transactions and enable debugging and error management which can be near impossible on networks that lack synchronicity.
There are many sources of accurate time for use with NTP time servers (Network Time Protocol). NTP servers tend to use time that is controlled by atomic clocks to ensure accuracy, and there are advantages and disadvantages to each system.
Ideally as a source of time you want it to be a source of UTC (Coordinated Universal Time) as this is the international time standard as used by computer systems worldwide. But UTC is not always accessible but there is an alternative.
GPS time is the time as relayed by the atomic clocks on board GPS satellites. These clocks form the basic technology for the Global Positioning System and their signals are what are used to work out positing information.
But GPS time signals can also provide an accurate source of time for computer networks – although strictly speaking GPS time does differ to UTC.
No Leap Seconds
GPS time is broadcast as an integer. The signal contains the number of seconds from when the GPS clocks were first turned on (January 1980).
Originally GPS time was set to UTC but since GPS satellite have been in space the last thirty years, unlike UTC, there has been no increase to account for leap seconds – so currently GPS is running exactly 17 seconds behind UTC.
Whilst GPS time and UTC are not strictly the same as they were originally based on the same time and only the lack of leap seconds not added to GPS makes the difference, and as this is exact in seconds, conversion of GPS time is simple.
Many GPS NTP servers will convert GPS time to UTC time (and local time if you so wish) ensuring you can always have an accurate, stable, secure and reliable source of atomic clock based time.
Atomic clocks are the most accurate timekeeping devices known to man. There accuracy is incomparable to other clocks and chronometers in that whilst even the most sophisticated electronic clock will drift by a second every week or two, the most modern atomic clocks can keep running for thousands of years and not lose even a fraction of a second.
The accuracy of an atomic clock is down to what they use as their basis for time measurement. Instead of relying on an electronic current running through a crystal like an electronic clock, an atomic clock uses the hyperfine transition of an atom in two energy states. Whilst this may sound complicated, it is just an unfaltering reverberation that ‘ticks’ over 9 billion times each second, every second.
But why such accuracy really necessary and what technologies are atomic clocks employed in?
It is by examining the technologies that utilise atomic clocks that we can see why such high levels of accuracy are required.
GPS – Satellite navigation
Satellite navigation is a huge industry now. Once just a technology for the military and aviators, GPS satellite navigation is now used by road users across the globe. However, the navigational information provided by satellite navigation systems like GPS is solely reliant on the accuracy of atomic clocks.
GPS works by triangulating several timing signals that are deployed from atomic clocks onboard the GPS satellites. By working out when the timing signal was released from the satellite the satellite navigational receiver can just how far away it is from the satellite and by using multiple signals calculate where it is in the world.
Because of these timing signals travel at the speed of light, just one second inaccuracy within the timing signals could lead to the positing information being thousands of miles out. It is testament to the accuracy of GPS atomic clocks that currently a satellite navigation receiver is accurate to within five metres.
Network Time Protocol (NTP) is a TCP/IP protocol developed when the internet was in its infancy. It was developed by David Mills of the University of Delaware who was trying to synchronise computers across a network with a degree of precision.
NTP is a UNIX based protocol but it has been ported to operate just as effectively on PCs and a version has been included with operating systems since Windows 2000 (including Windows 7, Vista and XP).
NTP, and the daemon (application) that controls it, is not just a method of passing the time around. Any system running the NTP daemon can act as a client by querying the reference time from other servers or it can make its own time available for other devices to use which in effect turns it into a time server itself. It can also act as a peer by collaborating with other peers to find the most stable and accurate time source to use.
One of the most flexible aspects of NTP is its hierarchical nature. NTP divides devices into strata, each stratum level is defined by its proximity to the reference clock (atomic clock). The atomic clock itself is a stratum 0 device, the closest device to it (often a dedicated NTP time server) is a stratum 1 device whilst other devices that connect to that become stratum 2. NTP can maintain accuracy to within 16 stratum levels.
Any network that needs to be synchronised, has to first identify and locate a time source for NTP to distribute. Internet sources of time are available but thee are often taken from stratum 2 devices that operate through the firewall. The only way NTP can peer the time is if the TCP/IP port is left open to allow the traffic through. This could lead to security issues as malicious users can take advantage of this firewall hole.
Dedicated NTP time servers find a source of time via GPS or radio signals and so don’t leave a network vulnerable to attack. By attaching a NTP time server to a router and entire network of hundreds and even thousands of devices can be synchronised thanks to NTP’s hierarchical structure.