Home Networking - Firewalls

Contractors use the word firewall for a physical barrier to keep the fire from spreading from one room to another. Home networks also have (or should have) firewalls. These hardware, software or a combination that protects a network from unauthorized access and malicious software.

computer firewall that protects the system in two ways. You can keep the programs to make Internet connections, which maintains an infected program or a virus spreading. More commonly, however, the purpose of the network firewall at home to keep the system safe outside attempts to access it. unauthorized access attempts can be obtained from the Internet, other computers on your home network or even "wardrivers" (hackers go through the computer without cables) that can simply be guided by a virus and networking.

Protect the network from certain types of access may make it harder for them even if they can access their course network.Of, blocking all traffic in both directions would be a useless network. Network security is a balance between maintaining some of the traffic to allow access to the traffic you want. Where exactly this balance is a difficult question. A number of more or less standard items that people should be careful when trying to implement effective systems of firewalls. The two most common are TCP and UDP protocols.

UDP is a transmission protocol and does not require any two-way connection. TCP, but is two directions. UDP can be input or output, for example when you ping a server. To open a port on the firewall, it is usually necessary to specify both the port number and protocol. What we should aim to close the doors we do not know for sure that you need to open. Only open ports or allow certain protocols in the direction you need - and only when you know what you do. Closed in both directions must be the rule, unless it is necessary.

HTTP: This is the standard protocol used for data applications on the Internet and send (upload) or receive (web pages, downloading). Your system should have opened port 80 for HTTP firewall. Secure HHTP (or HTTPS) uses port 443 instead. Port 8080 is also common to HTTP connections.

FTP is commonly used to transfer files across networks, you must open the port 20 to this Protocol.

Uses SMTP to send and receive email, this protocol requires port 25 to be opened.

POP3: Used for many email systems. Open port 110 for incoming POP3 traffic.

DNS: DNS needs to send and receive, to perform the function of translating IP addresses to domain names. Open port 53 in both directions for this important functionality.

DHCP: If your IP address is assigned dynamically, not static must open the door 68 to allow this protocol.

DOOM: If you play Doom, you'll have to open port 666. Otherwise, as with any other port that is not used, is closed in both directions.

Many other ports are used for various services, such as port 1433 (Microsoft SQL Server requires this). Any program that needs a particular port must be mentioned in the documentation. Be careful when you configure the network firewall system, why do provide good security for you!

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