14.5 Networks - Preserving Network Security

A large part of a network administrators job is making sure the areas on the network are secure from unauthorised users.

The trouble is, where there is a computer system, there is a cracker ready to try and beat your security.

Methods to try and secure systems include:
- Physical controls (locks, steel doors, removable hard drives, armed guards etc.)
- Procedural controls (password rules, network usage policies, access times)
- Software controls (firewalls, virus protection, data encryption, access levels, auditing/monitoring)

There are lots of ways crackers can try to gain access to a network, here are some of them:

• Password guessing (can be checked for strength against compromising. Click here)
• Brute force attacks
• Packet sniffers
• Virus/trojan horses/Phishing/Garbaging
• Physical access
• Corrupting staff/legitimate users
  

But there will always be a loop hole ready to be exploited. The trick is, making sure you know when you have been cracked!

After putting together a set of operational procedures, checks on staff, latest software patches and up-to-date virus/firewall software, all the network administrator can do is monitor the network for strange behaviour which might indicate an attack - this can be automatically using network auditing software.