Network Security Tips and Tricks

 Network security covers a range of topics. It is a wide area that covers everything from the design of a network to security all the entry points to group policies to educating users about using the network safely. Network security also includes auditing security policies and redesigning these policies to meet the advancements in technology and to counter the possible threats to the central database. The following paragraphs offer tips on each of these factors, including the security design life cycle.

The network security design life cycle begins with the design of the network or sometimes even prior to designing the network. This helps in selecting the right components for the network based on the network scale and use. These components include both software (encryption software, etc.) and hardware (routers, firewalls, etc). Once the network is created, the security design is implemented to keep the network and its components (hardware, software, and users) safe. The security design also includes the creation of group policies and assignment thereof. Another important part of network security implementation is to keep an eye on the activities on the network – both to find flaws and to locate users who are trying to manipulate the network from within. Another important aspect is to keep on testing the network for possible vulnerabilities in a network and create patches to deal with each such vulnerability.

Please read my article, Best Practices in IT Risk Management, for more information on network security design implementation.

As explained in the previous section, auditing is an integral part of securing the network. It helps in checking out the possible problems in your current network. Once identified, network engineers can alter the network design or use special software/hardware to eliminate the problems. Auditing can be done in several ways. The best method is logging, which is where the admins can study the behavior of each component in the network and log it in different files. The files should never be stored on the main server or on any computer connected to the network. The best method is to store these logs on a standalone computer so that no one can access it except the network admins. Plenty of software exists to make auditing easier. Check out this review of GFI LANGuard and see if it meets your audit needs.

Network printers often contain Telnet, FTP, and WEB as part of their firmware. These can easily be exploited. Most admins neglect this factor as they do not think that the printers can be exploited. But hackers can damage the entire network if they gain access to the firmware. It is always better to block the printer ports using a boundary firewall thereby reducing the chances of exploitation. If these services are not required, the best way is to turn them off.

Network Perimeters and Firewalls are an important part of any network and hence, admins should stress more security on these factors. These serve as the primary line of defense so they should be more tightened to reduce infiltration possibilities. Some of the basic tips while dealing with these defense lines are:

1. Close down any unnecessary TCP/UDP servers on the router/firewalls;
2. For active servers employing TCP/UDP, you need to ensure that the access is very limited – only to the highest level of network administration;
3. Check out the services on the active servers. Shut down any service that is not required. These include source routing, remote configuration, etc;
4. Keep a watch on all the interfaces of the router/firewalls. Shut down any un-used interface. Provide ample protection to the active interfaces to prevent exploitation – both from within and outside the organization;
5. Most importantly, make sure that the password on each of the pioneer defense lines (routers/firewall) are set to expire at regular intervals.

While these can be considered best network security practices, please read our article on Limitations of Firewalls to understand that you also need to keep a manual watch on these interfaces.

Please turn to next page for more general but important tips for maximum network security.