| Network security is vitally important for most business | | | | either fail to realise the importance of synchronization |
| systems. Whilst email viruses and denial-of-service | | | | between all devices on a network. Failing to |
| attacks (DoS attack) may cause us headaches on our | | | | synchronize a network is often a common security |
| home systems, for businesses, these sorts of attacks | | | | issue. Not only can malicious users take advantage of |
| can cripple a network for days - costing businesses | | | | computers running at different times but if a network is |
| hundreds of millions each year in lost revenue. | | | | struck by an attack, identifying and rectifying the |
| Keeping a network secure to prevent this type of | | | | problem can be near impossible if every device is |
| malicious attack is usually of paramount importance for | | | | running on a different time. |
| network administrators, and while most invest heavily in | | | | Even when a network administrator is aware of the |
| some forms of security measures there is often | | | | importance of time synchronization they often make a |
| vulnerabilities inadvertently left exposed. | | | | common security mistake when attempting to |
| Firewalls are the best place to begin when you are | | | | synchronize their network. Instead of investing in a |
| trying to develop a secure network. A firewall can be | | | | dedicated time server that receives a secure source |
| implemented in either hardware or software, or most | | | | of UTC (Coordinated Universal Time) externally from |
| commonly a combination of both. Firewalls are used to | | | | their network using atomic clock sources like GPS, |
| prevent unauthorized users from accessing private | | | | some network administrators opt to use a shortcut |
| networks connected to the Internet, especially local | | | | and use a source of Internet time. |
| intranets. All traffic entering or leaving the intranet pass | | | | There are two major security issues in using the |
| through the firewall, which examines each message | | | | Internet as a time server. Firstly, to allow the time code |
| and blocks those that do not meet the specified | | | | through the network a UDP port (123) has to be left |
| criteria. | | | | open in the firewall. This can be taken advantage of |
| Anti-virus software works in two ways. Firstly it acts | | | | by malicious users who can use this open port as an |
| similarly to a firewall by blocking anything that is | | | | entrance to the network. Secondly, the inbuilt security |
| identified in its database as possibly malicious (viruses, | | | | measure used by the time protocol NTP, known as |
| Trojans, spyware etc). Secondly Anti-virus software is | | | | authentication, doesn't work across the Internet which |
| used to detect, and remove existing malware on a | | | | means that NTP has no guarantee the time signal is |
| network or workstation. | | | | coming from where it is supposed to. |
| One of the most over-looked aspects of network | | | | To ensure your network is secure isn't it time you |
| security is time synchronization. Network administrators | | | | invested in an external dedicated NTP time server? |