What does about advanced timing mean

Archive for the category 'Advanced NTP'

Keeping Your Network Safe A Beginner's Guide

Wednesday September 30th, 2009

Network security is critical to most business systems. While email viruses and Denial-of-Service (DoS) attacks can give us headaches on our home systems, these types of attacks can cripple a network for days - costing companies hundreds of millions of lost revenue each year.

Securing a network that prevents such malicious attacks is usually of the utmost importance to network administrators. While most invest in certain forms of security, there are often security loopholes that accidentally stay open.

Firewalls are the best place to start when building a secure network. A firewall can be implemented in either hardware or software, or usually a combination of both. Firewalls are used to prevent unauthorized users from accessing private networks connected to the Internet, especially local intranets. All traffic entering or leaving the intranet passes through the firewall, which examines every message and blocks those that do not meet the specified criteria.

Antivirus software works in two ways. First, it acts much like a firewall in that it blocks everything that is identified as potentially malicious in its database (viruses, Trojans, spyware, etc.). Second, antivirus software is used to detect and remove malware present on a network or workstation.

One of the most overlooked aspects of network security is time synchronization. Network administrators do not recognize the importance of synchronization between all devices on a network. Synchronizing a network is often a common security problem. Not only can malicious users take advantage of computers running at different times, but if a network is affected by an attack, identifying and correcting the problem can be nearly impossible if each device is running at a different time.

Even if a network administrator understands the importance of time synchronization, they often make a common security mistake when trying to synchronize their network. Instead of investing in a dedicated time server that has a secure source of UTC (Coordinated Universal Time) external to their network with atomic clock sources like GPS, some network administrators choose to use a shortcut and use a source of Internet time.

There are two major security issues with using the Internet as a time server. To enable timecode over the network, a UDP port (123) must first be left open in the firewall. This can be exploited by malicious users who can use this open port to access the network. Second, the built-in security measure used by the time protocol, NTP, known as authentication, does not work over the Internet, which means that NTP has no guarantee that the time signal is from where it is supposed to come from.

To make sure your network is secure, isn't it time to invest in an external system dedicated to NTP time servers?

Posted in advanced NTP, atomic clocks, chronology, network security, NTP configuration, NTP server, time server, timing source | Comments Off Keeping Your Network Safe A Beginner's Guide

Configuring a Network to Use an NTP Server Part Two: Distributing the Time

Thursday September 3rd, 2009

NTP (Network Time Protocol) is the protocol for time distribution in a network. NTP is hierarchical. It organizes a network in layers that are the distance from a clock source and the device.

A dedicated NTP server that receives the time from a UTC source such as GPS or the national time and frequency signals is considered a Stratum 1 device. Any device connected to an NTP server becomes a Stratum 2 device, and devices further down the chain become Stratum 2, 3, and so on.

Layer layers exist to prevent cyclical dependencies in the hierarchy. But the layer height is not an indication of quality or reliability.

NTP checks the time on all devices on the network and adjusts the time based on how much drift it detects. But NTP goes further than just checking the time on a reference clock, the NTP program exchanges time information according to packets (data blocks), but refuses to believe the time until several exchanges have taken place, each of which passes a series of tests known as the Protocol Specifications. It often takes about five good samples for an NTP server to be accepted as a timing source.

NTP uses timestamps to represent the current time of day. Since time is linear, each timestamp is always greater than the previous one. NTP timestamps come in two formats, but they derive the seconds from a specified point in time (known as the prime epoch, set on 00:00 January 1, 1900 for UTC). The NTP algorithm then uses this time stamp to determine the progress or retraction of the system or network clock.

NTP analyzes the timestamp values ​​including the frequency of errors and stability. AN NTP server will maintain an estimate of the quality of both its reference clocks and itself.

Posted in Advanced NTP, NTP Applications, NTP Configuration, NTP Server, Timing Source | Comments Off Configuring a Network to Use an NTP Server Part Two: Distributing Time

Configuring a Network to Use an NTP Server Part 1: Finding a Time Source

Tuesday September 1st, 2009

It is crucial for modern networking that your network is synchronized with the right time. Because of the value of time stamps in global communication and across multiple networks, it is imperative that every machine has a source of UTC (Coordinated Universal Time).

UTC was designed to allow the entire world community to share the same time no matter where they are on the globe, as UTC does not use time zones, so accurate communication is possible regardless of location.

However, when trying to find a source of UTC, some network administrators often pounce on it to sync a network. There are many areas from which a source can be received from UTC, but only a few that provide an accurate and secure reference to time.

The Internet is replete with alleged sources of UTC, but many of them nowhere near their celebrated accuracy. In addition, access to the Internet can lead to security gaps.

Internet time sources are outside the firewall, so a hole must be left open for malicious users to exploit. Additionally, NTP, the protocol used to distribute and receive time sources, cannot initiate its authentication security measure over the Internet, so there is no way to ensure that time comes from where it is needed.

External sources of UTC time are far more secure. Most administrators use two methods. Longwave radio signals such as those sent by national physics laboratories and the GPS signal that is available around the globe.

The external sources of UTC ensure your safety NTP network not only receives an accurate UTC source, but also a secure one.

Posted in Advanced NTP, Chronology, Network Security, NTP Basics, NTP Configuration | Comments Off Configuring a Network to Use an NTP Server Part 1: Finding a Time Source

Perfect time synchronization for Windows

Wednesday July 29th, 2009

Most Windows operating systems have a built-in time synchronization service that is installed by default and can synchronize the machine or a network. For security reasons, however, among other things, Microsoft strongly recommends using an external time source.

NTP time server securely and accurately the UTC time signal from the GPS network or the WWVB radio broadcasts (or European alternatives). NTP time servers can synchronize a single Windows machine or an entire network within a fraction of a second of the correct UTC time (Coordinated Universal Time).

An NTP time server provides precise timing information 24 hours a day, 365 days a year across the globe. A dedicated NTP time server is the only safe, secure, and reliable method of synchronizing a computer network using Coordinated Universal Time (UTC). Outside the firewall, an NTP time server, unlike Internet timing sources, does not allow a computer system to become susceptible to malicious attacks via the TCP / IP port.

An NTP time server is not only secure, it receives a UTC time signal directly from atomic clocks, unlike internet timing sources, which are time servers themselves. NTP servers and other time synchronization tools can synchronize entire networks, individual PCs, routers and a whole host of other devices. Using either GPS or the North American WWVB signal, a dedicated NTP time server ensures that all of your devices are running within a fraction of UTC time.

An NTP time server will:

• Increase network security
• Prevent data loss
• Enable logging and tracking of errors or security breaches
• Reduce the confusion in shared files
• Avoid errors in billing systems and time-critical transactions
• Can be used to provide indisputable evidence in legal and financial disputes

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Differences in time

Tuesday July 14th, 2009

We are all aware of the differences in time zones. Anyone who has traveled across the Atlantic or Pacific will feel the effects of jet lag caused by having to set our own internal body clocks. In some countries, like the USA, there are multiple time zones in one country, which means that the time from the east coast to the west is a few hours.

This difference in time zones can cause confusion, but for residents of countries that span more than one time zone, they will soon adapt to the situation. However, there are more time scales and time differences than just time zones.

For decades, different time standards have been developed in order to do justice to time zone differences and to enable a single time standard that the whole world can synchronize. Unfortunately, since standards such as British Railway Time and Greenwich Mean Time were first developed, other standards have been developed to accommodate different applications.

One of the problems with developing a time standard is deciding what to base it on. Traditionally, all time systems were developed on the rotation of the earth (24 hours). After the development of atomic clocks, it quickly became apparent that no two days are exactly the same length and often fail to reach the expected 24 hours.

New time standards were then developed based on atomic clocks, as they were found to be far more reliable and accurate than using the earth's rotation as a starting point. Here is a list of the most common time standards. They are divided into two types based on the rotation of the earth and based on atomic clocks:

Time standards based on the rotation of the earth
The true solar time is based on the sunny day - is the period between one solar noon and the next.

The sidereal time is based on the stars. A sidereal day is the time it takes the earth to make a revolution in terms of the stars (not the sun).

Greenwich Mean Time (GMT) based on when the sun is highest (noon) above the Prime Meridian (often referred to as the Greenwich Meridian). GMT was an international time standard before the advent of precise atomic clocks.

Time standards based on atomic clocks

International Atomic Time (TAI) is the international time standard from which the time standards including UTC are calculated. TAI is based on a constellation of atomic clocks from around the world.

GPS time GPS time, also based on TAI, is the time indicated by atomic clocks on board GPS satellites. Originally like UTC, the GPS time is currently 17 seconds (accurate) behind, as 17 leap seconds have been added to UTC since the satellites started.
Coordinated Universal Time (UTC) is based on both atomic time and GMT. To counteract the inaccuracy of the earth's rotation, additional jump seconds are added to UTC, but time is derived from TAI to make it as accurate.

UTC is the true commercial time frame. Computer systems around the world synchronize with UTC using NTP time servers. These dedicated devices get the time from an atomic clock (either through GPS or special radio transmissions from organizations like NIST or NPL).

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Dealing with time computer synchronization and timestamps

Tuesday June 30th, 2009

Time is important for the smooth running of our daily life. Everything we do is either controlled or restricted due to time constraints. But time is even more important to computer systems because it is the only reference point a computer must distinguish between events and processes.

Everything a computer does is logged by the processor, with which process and when exactly it was executed. Because computers can process hundreds, if not thousands of transactions per second, the timestamp is critical in determining the order of events.

Computers do not read or use time in the same format as we do. A computer time stamp is in the form of a single digit that counts the number of seconds from a given point in time. In most systems this is referred to as the 'prime epoch' and is set from 00: 00: 00 UTC on January 1, 1970. So a timestamp for the date June 23, 2009 the timestamp would read: 1246277483 as this is the number of seconds from the prime epoch.

Computer time stamps are sent over networks and the Internet, for example a time stamp is provided every time an email is sent. When the email is answered, it comes with a timestamp. However, if neither computer is synchronized, the reply email could come back with an earlier code and this can create a myriad of confusion for one computer as the email according to its logs came back before the original was sent.

For this reason, computer networks are synchronized with the global time scale UTC (Coordinated Universal Time). UTC is maintained by a constellation of atomic clocks, which means that the computer network that is synchronized with a UTC source is very accurate.

Time synchronization on computers is handled with the NTP (Network Time Protocol) protocol. Special dedicated NTP servers are available that take a secure time code either from the GPS network or from special radio transmissions broadcast by national physical laboratories, and then synchronize entire networks with the single time source.

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Do I really need an NTP time server?

Sunday June 14th, 2009

The NTP time server is a much misunderstood device. They are quite simple devices in the sense that they are used for the purpose of time synchronization by getting an external source of the time which is then distributed over a computer network NTP (Network Time Protocol).

However, with a plethora of "free" time servers available on the Internet, many network administrators are making the decision that NTP time servers are not a necessary device and that their network can do without them. However, there are a large number of pitfalls in relying on the internet as a time reference; Microsoft and the US Physics Laboratory NIST (National Institute for Standards and Time) highly recommend external NTP time servers instead of Internet providers.

Here is what Microsoft says:
"It is highly recommended that you configure the authoritative time server to collect time from a hardware source. If you configure the authoritative time server to synchronize with an Internet time source, there is no authentication."

Authentication is a security measure implemented by NTP to ensure that the time signal sent comes from where it is supposed to come from. In other words, authentication is the first line of defense in protecting against malicious users. There are other security issues with using the internet as a time source as well, as any communication with an internet time source requires that the TCP / IP port in the firewall be left open, which could also be tampered with by malicious users.

NIST also recognizes the importance of the NTP time server systems for prevention and detection of security threats they suggest in their Guide to Computer Security Log Management:
"Organizations should use time synchronization technologies such as Network Time Protocol (NTP) servers whenever possible to keep the clock signals from the protocol sources consistent."

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Reported GPS fears should not affect the time synchronization

Wednesday, May 27th, 2009

Following recent media reports Due to a lack of investment in the US global navigation satellite system - GPS (Global Positioning System) and the possible failure of navigation receivers in recent years, Galleon Systems, the specialist in time synchronization, would like to reassure all of its customers that the GPS is not working on the network does not affect the current status of the GPS NTP time server.

Recent media reports, according to a GAO study that sparked mismanagement and lack of investment, caused some of the current 31 satellites to fall below 2012 in 24 and 2011, affecting their accuracy.

However, the UK National Physical Laboratory are confident that potential problems with GPS navigational equipment are not those of GPS NTP servers.

A spokesman for the UK's National Physical Laboratory confirmed that timing information should be unaffected by possible future satellite failures.

"It is estimated that there is a 20% risk that in 2011-2012 the number of satellites in the GPS constellation could temporarily drop below 24.

"If that happened, the positional accuracy of GPS receivers could degrade slightly at certain points, and in particular, they might take longer to get repaired in some places when first powered up. But even then, the effect would be closer a performance degradation rather than a complete failure.

"A GPS timing receiver is unlikely to be significantly affected because any satellite that is observed, once it has determined its position, will provide it with useful timing information. A small decrease in the number of satellites being viewed should not greatly improve its performance affect. "

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The world in perfect synchronization

Wednesday, May 13th, 2009

We know synchronization every day in our life. Go down from the freeway to the crowded street; We automatically adjust our behavior to synchronize with those around us. We drive in the same direction or use the same thoroughfares as other commuters as this would make our journey much more difficult (and dangerous).

When it comes to timing, synchronization is even more important. Even in our day-to-day business, we expect adequate synchronization from people. If a meeting starts at 10am, we expect everyone to be there within a few minutes.

However, when it comes to computer transactions over a network, synchronization accuracy becomes even more important when accuracy to a few seconds is too low and synchronization to milliseconds is required.

Computers spend time on every transaction and process they do, and you only need to think of the turmoil caused by the Millennium Bug to appreciate the importance of the computer in a timely manner. If there is not enough synchronization, all kinds of errors and problems can arise, especially with time-sensitive transactions.

Not only are transactions that can fail without proper synchronization, but also timestamps in computer log files. So if something goes wrong or a malicious user intrudes (which is very easy without proper syncing) it can take a long time to go wrong and even longer to fix the issues.

A lack of synchronization can also have other repercussions, such as data loss or failed data recovery, and can also leave a company defenseless in a potential legal dispute as a bad or unsynchronized network is impossible to audit.

However, millisecond synchronization is not the problem many administrators assume. Many choose to use many online time servers available on the Internet, but doing so can create more problems than they can solve, such as leaving the UDP port open in the firewall (to let the timing information through ). to mention no guaranteed level of accuracy from the public time server.

A better and simpler solution is to use a dedicated network time server that uses the NTP (network time protocol) protocol A NTP time server It is plugged directly into a network and uses GPS (Global Positioning System) or special radio transmissions to get the time directly from an atomic clock to receive and to distribute in the network.

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The concept of time

Monday, May 11th, 2009

Time is something we are all familiar with, it rules our lives even more than money, and we are constantly at war with time as we strive to get our daily chores done before it runs out.

But when we begin to examine time, we discover that in the concept of time we begin to see that a never-ending linear distance between different events that we call time is a purely human invention.

Of course there is time, but it certainly does not follow the rules of the human understanding of time. It is never ending or constant and changes and curves according to the speed of the observer and the pull of gravity. In fact, it was Einstein's theories of relativity that gave humanity its first glimpse into the time it really is and how it affects our daily lives.

Einstein described a four-dimensional space-time in which time and space are inextricably linked. This spacetime is warped and warped by the slowing down of time (or our perception of it). Einstein also said that the speed of light is the only constant in the universe and that time changes depending on the relative speed.

When it comes to keeping track of time, Einstein's theories can hamper any attempt at chronology. When both gravity and relative speed can affect time, it becomes difficult to measure time accurately.

We long ago abandoned the idea of ​​using the celestial bodies and the Earth's rotation as references for our timekeeping, as it was recognized at the beginning of the 20th century that the Earth's rotation was not accurate or reliable at all. Instead, we rely on the oscillations of the atoms to keep track of time. Atomic clocks measure the atomic ticks of certain atoms, and our concept of time is based on these ticks, with over 9 billion oscillations of the cesium atom every second.

Even if we are now relying on atomic vibrations, technologies such as GPS satellites (Global Positioning System) have yet to counteract the effects of lower gravity. In fact, thanks to atomic clocks, the effects of time can be tracked so closely that those at different heights above sea level run at slightly different speeds that need to be compensated.

Atomic clocks can also be used to synchronize a computer network so that they run as accurately as possible. Most NTP time servers work by using the time signal sent by an atomic clock (either by GPS or long wave) using the NTP (Network Time Protocol) protocol.

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