In this tutorial we will discuss the concept of Ports and how they work with IP addresses. If you have not read our article on IP addresses and need a brush up, you can find the article here. If you ...

If you are a network engineer or a normal user, you may need to find, open or block a virtual port, such as a TCP or a UDP port for an application. Virtual ports help you manage your network hardware ...

A number from 0 through 1023 used to identify a network service on a private IP network or the public Internet. Residing in a field in the TCP or UDP header, the port number directs packets to the ...

Security practitioners for decades have advised people to limit DNS queries against their DNS servers to only use UDP port 53. The reality is that DNS queries can also use TCP port 53 if UDP port 53 ...

What is TCP/UDP port 27? I've looked it up in IANA's list of well-known ports and it came up as nsw-fe, or more appropriately, "NSW User System FE", but just what the hell is it? I've been told it was ...

PortExpert is a free application that can give very useful information about all TCP, UDP communications connected to the system and is hence useful to identify potential threats. These days we are ...

When working with the Cisco IOS, it’s very important to know your TCP and UDP port numbers. This is especially true when creating IOS access control lists (ACLs). Let’s take a closer look. What’s a ...