Time is essential to all of us, and losing track of time can be costly. Missing meetings, being late for work or not catching the last bus home can all be a nuisance, but all this pales in comparison to what happens when a computer network loses track of time.
Time is critical for computer systems. It is the only reference a network has for knowing when applications and processes need to be, or have been, done. Alter the network time, allow the clocks to drift or fail to synchronise everything properly and a whole host of problems can arise.
Affects of Time Failure
Firstly, if network time goes wrong, processes and applications due to take place may not happen. This is because if the time is wrong a PC may assume the application has already happened. Secondly, data can easily be lost as timestamps are used in the storing process, and if there is a problem with the time, data may just get dumped. Thirdly, when it comes to debugging a system, without accurate synchronisation it can be nearly impossible. Knowing when something went wrong is essential for any error correction.
Finally, network security is reliant on secure and accurate time. Hackers and malicious software can use any discrepancies in a system’s time to gain access to a network. It only takes a second or two of discrepancy to provide enough access to unauthorised access. And if the time source itself is attacked, the effects can be even more severe
Time Server Security
Many computer networks use online NTP time servers (Network Time Protocol). These are accessed across the internet and send a regular timestamp to which a network synchronises. The problem with these online time server systems is that if the time server is wrong, so the network will be. Also, if a time server itself gets attacked by hackers or malicious software, the effects can be catastrophic. Imagine you network suddenly thinking it’s a year in the future, or in the past, the entire network could be open to all sorts of abuse.
The accuracy of these online time servers can never be guaranteed and are affected by all sorts of things such as the distance away, and the speed of the connection, and they also require an open port in the firewall, through which they send their time signals, and this port could also be used by malicious users.
The NTP Time Server
The solution for ensuring network security is fairly simple and relatively inexpensive – the NTP time server. These dedicated devices receive the time directly from an atomic clock source such as the GPS network (Global Positioning System). This not only makes them highly secure methods of synchronising network time, but also highly accurate, often to within a few milliseconds.
The cost of an NTP server is relatively low, especially when you consider the cost of failing to have accurate and secure network time will cost you. As a single NTP server is able to synchronise a network of hundreds of machines, securely, and offers peace of mind and a cost effective and secure method of keeping your network healthy.