But most companies know this don’t they? More than likely, yes. So they use a firewall to protect themselves don’t they? Probably. Well they’re safe then, and can sit back and put their feet up, can’t they? No.
All organisations need to protect the valuable data and documents held on their network, and a firewall is the most efficient way to do this. Acting as guards, firewalls monitor and examine traffic between a network and the Internet. Any unauthorised or suspicious traffic is blocked. Firewalls can also be configured to secure one network from another. However, correct management is crucial. The firewall can become less than 30% effective within three months of installation if managed incorrectly.
A firewall is simply an enforcement device. It does not provide security in its own right. The actual firewall device provides approximately 20% of the security capability. It is the way the firewall is configured that provides the overall security effectiveness. It’s a bit like having locks on all the windows and doors in a house but then leaving the key in the door, or one of the windows open. The locks only work if time is taken to ensure that all windows and doors are closed and all the keys are removed.
The best way to achieve security effectiveness is to design a security policy. This will ensure the integrity of any mission critical device - especially firewalls. Below is a guide on how to create a firewall policy.
5 Tips to generating a firewall policy
1. Identify trust zones
The very first step in securing a network is to decide on the different zones of trust present. In its most basic form, network security is about zones of trust. A simple example would be the Internet (a ‘no trust’ zone) and an internal network (a ‘high trust’ zone); a firewall controls traffic between these different zones of trust. Of course, in the real world there are more than two zones. Typically these include Internet, web servers, external connection zone, internal network, and remote access zone. Once the zones are identified the different traffic flowing between the zones can be defined and the firewall policy can be configured accordingly.
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