IPv6 Unicast Addresses
The 3 categories of IPv6 addresses are:Unicast identifies a single interface. A packet sent to a unicast address is delivered to the interface identified by that address. Multicast identifies a group of interfaces. A packet sent to a multicast address is delivered to all interfaces identified by that address. Anycast identifies a group of interfaces. A packet sent to an anycast address is delivered to the closest member of a group. More ...
Virtual Local Area Networks (VLANs)
A Virtual LAN (VLAN) is a subgroup within a local network. VLANs make it easy for network administrators to separate a single switched network into subnetworks to match the functional and security requirements of their network without having to make major changes in the existing network infrastructure. More ...
Ports and Sockets
Data transmitted over the Internet carries a 32-bit IP address that identifies its destination computer and a 16-bit number that identifies a port on that computer. The combination of the IP address and the port number is called a socket. A pair of sockets, one on the sending computer and one on the receiving computer uniquely identifies a specific connection on the Internet. More ...
A Simple Description of the IPv6 Header and Datagram
This article provides a simple description of the IPv6 header and datagram without a lot referring back to IPv4. More ...
The OSI Reference Model
No real world network operating systems conform exactly to the OSI model, but it is useful as a reference when describing existing systems. It is difficult to study network devices such as routers, switches, and gateways without using the model. More ...
IPv6 Address Format
IPv4 is running out of addresses. IPv6 was designed to solve this problem therefore it is important
to understand the format of an IPv6 address. More ...
Understanding IP Routing
The Transmission Control Protocol/Internet Protocol TCP/IP suite of protocols is the underlying technology for information exchange on the Internet. This essential reference shows you how to isolate and resolve common network failures and to sustain optimal network operation. More ...
What's the Difference Between a Packet and a Frame?
When speaking of the data in a network, people often call everything a packet. A more proper generic term would be protocol data unit or PDU. The specific name for a PDU depends on at what layer the data unit is in the OSI model. More ...
Video - Network Layer (Layer 3) of OSI Networking Model
In this video by Kevin Wallace you learn about the Network Layer of the OSI networking model. More ...
Network Cabling and Components
Although the power and sophistication of networking protocols and software is impressive, a network could not operate without physical cable and components. Even a wireless network needs physical components such as access points. More ...
Routing Datagrams
Systems can deliver packets only to other devices attached to the same physical network. A gateway is a network point, referred to as a router, that acts as an entrance to another network. More ...
Protocol Suites
Network protocols define rules for handling data and communicating in a particular networking environment. Individual protocols operate at specific layers in the OSI reference model. A protocol suite is a group of protocols designed to work together. More ...
Network Switches
A bridge or router may be referred to as a switch because it uses information in the data packet to choose a path from one network segment to another. A bridge may be referred to as a layer 2 switch because it uses information from layer 2, the Data Link layer of the OSI model. More ...
Session Border Controllers - More Than Just a Voice Firewall
The migration from Time-Division Multiplexing to the more flexible IP based SIP networks brought an unexpected security challenge. Session Border Controllers focused primarily on SIP and H.323 session security. More ...
The OSI Presentation Layer
At this layer applications communicate on a format for exchanging data. The Session layer provides character set conversion and formats the data. It performs encryption and decryption, compression and decompression. More ...
