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How A Port Scan Works network critical

With many new security threats arriving everyday, protecting your computer and digital files is even more important. One threat today is port scanning. Port scanning happens to most people whether they realize it or not. Protecting yourself against port scans can help you secure your system from malicious users.

All computers have ports, and services run on these ports. When your computer needs to connect to your mail server in order to check your email, it will open one of these ports and make a connection to download your new email. However sometimes these ports are always on and listening. A port scan occurs when an attacker scans a host to see which ports are open and which are closed or not in use.

Think of a port scan like checking doors and windows of your house to see if it is locked or not. While the attacker may not break into your house he may know that there is a window unlocked and entry can be achieved easily. A port scanner works in much the same way as it checks ports on your computer to see which is closed or open. It is not illegal in most places to do a port scan because basically your just checking if the connection can be made and not actually making a connection to the host. However it is possible to create a Denial of Service attack if port scans are made repeatedly.

Many firewalls can protect you against port scans. A firewall is a program that monitors outgoing and incoming connections to your computer. A firewall may open all ports on your system to effectively stop scans from showing any ports. While this approach works in many cases. Port Scans have advanced with new techniques such as ICMP port unreachable scans, and NULL scans. While its best to try and filter all port scans to your computer, its also important to realize that any ports that are open and listening need to be investigated.

Leaving open ports on your machine can lead to a system compromise causing lost data, and possibly identity theft. A port scan of your own system can show you exactly what an attacker sees and what sort of action you need to take to prevent an attack on your system.

One of the most popular port scanners available today is NMap from NMap is available for free download and is available for UNIX and Windows based systems. Its important to understand how NMap works so you can take the same approach as an attacker would against you. There are other port scanning software available and each has their own port scanning features. However NMap is by far the most popular and is loaded with features and different sorts of port scans you can perform.

While a port scan may not mean your system is about to be attacked. Its important to note that if a port scan occurs, someone knows about a weakness in your system if there is one. This thought alone is enough to consider auditing your firewall for port scan attempts.

3 Tips for Keeping a Network Secure network critical


There are many ways to keep a network secure and in terms of priorities that should definitely be one of the highest ones on the list for both small and large corporations. Even individuals that are looking for a way to protect information on their computer should look into the idea of keeping their network secure. There are many ways to go about doing this and indeed whole courses at schools are dedicated to this one simple concept, but there are definitely three tips that will help you get things started.

Tip #1: Outsource

This is perhaps the tip that applies most to larger and medium sized corporations and less to individuals and small businesses, but it is definitely the ideal as far as handling the situation goes. Keeping a network secure is one of the most difficult things a person can do and because of this people train for years at University and other post secondary institutions in order to be able to handle these things. People can actually take a decade or more to earn their Ph. D. in Computer Science and if you have the ability, why not benefit from all of their hard work and experience? The only problem with outsourcing (or delegating as some people like to call it) is that it can be expensive to the point where many will not be able to afford it.

Tip #2: Universal Redundant Password Protection

For people that do not have the ability to outsource, the single most important thing you can do to keep your network secure is to password protect everything. Password protect logon procedures, password protect access to higher security information and protect anything else that you think might be an eventual target of a network breach. If you want to get really serious about security, redundant password protection might also be a good idea. This is where you password protect different aspects of a network such that they might end up overlapping for a person trying to retrieve a specific piece of information or perform a specific task. It might get annoying to have to go through two or three password prompts in a half an hour period, but it will also go a long way towards keeping your network secure.

Tip #3: Maintenance

Finally, the last thing you can do to really help yourself along is to regularly perform maintenance on the hardware components of your network. Whether you are using wireless or wired access to the internet, it is important that you not only keep your hardware in good working order, but upgrade components at regular intervals. With the speed at which technology becomes obsolete in today’s world, threats against the security of your network are going to become more sophisticated as time rolls on. This makes it important to keep your network up to date. If you do not have the budget to upgrade it every few years or so, make sure you prioritize and then cyclically upgrade the components so that over every five or six year rolling period you’ve upgraded each part of the network at least once. It might seem expensive, but it will also help you with network security.


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