Category: Networking

Networking

Time-to-live (TTL)

Time-to-live (TTL)

Time-to-live (TTL) is a value in an Internet Protocol (IP) packet that tells a network router whether or not the packet has been in the network too long and should be discarded. For a...

HTTP Error 503 – Service unavailable

HTTP Error 503 – Service unavailable

The Web server (running the Web site) is currently unable to handle the HTTP request due to a temporary overloading or maintenance of the server. The implication is that this is a temporary condition...

what is Virtual Lan (VLAN)

what is Virtual Lan (VLAN)

Virtual Local Area Network, Virtual LAN or VLAN are network of computers that behave as if they are connected to the same wire even though they may actually be physically located on different segments...

Understanding Apache Access Log

Understanding Apache Access Log

Combined Log Format Whevever someone accesses your website it records a Combined Log Format. It is in the format as follows. LogFormat “%h %l %u %t \”%r\” %>s %b \”%{Referer}i\” \”%{User-agent}i\”” combined 1. %h...

Denial of Service attack

Denial of Service attack

DoS attack, denial-of-service attack, is an explicit attempt to make a computer resource unavailable by either injecting a computer virus or flooding the network with useless traffic. There are two types of DoS attacks:...

Proxy Server

Proxy Server

Proxy server is a computer that sits between a client computer and a real server, and provide indirect network services to a client. A proxy server intercepts all client requests, and provide responses from...

IPCONFIG

IPCONFIG

Ipconfig is a MS-DOS command-line tool used to display and manage the network settings of your computer. Ipconfig is available on Windows machines, and it displays the current network connection details and DHCP client...

What is DHCP

What is DHCP

DHCP stands for (Dynamic Host Configuration Protocol).   DHCP, Dynamic Host Configuration Protocol, is a communications protocol that dynamically assigns unique IP addresses to network devices. As a network device joins or leaves an...

What is TCP/IP?

What is TCP/IP?

TCP/IP, Transmission Control Protocol/Internet Protocol, is a suite of communications protocols used to interconnect network devices on the Internet. TCP/IP implements layers of protocol stacks, and each layer provides a well-defined network services to...

What is MAC Address?

What is MAC Address?

MAC, Media Access Control, address is a globally unique identifier assigned to network devices, and therefore it is often referred to as hardware or physical address. MAC addresses are 6-byte (48-bits) in length, and...

Subnetting Network

Subnetting Network

Here is another scenario where subnetting is needed. Pretend that a web host with a Class C network needs to divide the network so that parts of the network can be leased to its...

What is Subnet Mask?

What is Subnet Mask?

An IP address has two components, the network address and the host address. A subnet mask separates the IP address into the network and host addresses (). Subnetting further divides the host part of...

Public and Private IP Addresses

Public and Private IP Addresses

In order to maintain uniqueness within global namespace, the IP addresses are publicly registered with the Network Information Center (NIC) to avoid address conflicts. Devices that need to be publicly identified such as web...

What is IP Address?

What is IP Address?

Internet Protocol Address (or IP Address) is an unique address that computing devices use to identify itself and communicate with other devices in the Internet Protocol network. Any device connected to the IP network...