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 ...
IPv6 Neighbor Discovery Protocol (NDP)
Neighbor Discovery Protocol (NDP) is used by IPv6 hosts for Router Discovery, Neighbor Discovery and Duplicate Address Discovery. More ...
OSI Transport Layer
The Transport layer (OSI layer 4) uses connection-oriented protocols to provide a reliable end-to-end connection between the source computer and the destination computer. Transmission Control Protocol (TCP) is a transport layer protocol. 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 ...
OSI Network Model
The OSI model was developed years ago as a reference for network protocol and application designers to build their products with an open standard. That would promote a standard for developing network devices, interfaces, applications and services that would work together. It is a model rather than a specification since it defines layers and services for those layers and how each layer works with the layer above and below it. More ...
VTP (VLAN Trunking Protocol)
A VLAN (Virtual LAN) allows a network administrator to partition a LAN to conform to the business functions of the organization without physically modifying the network. VTP (VLAN Trunking Protocol) is a Cisco proprietary protocol that allows an administrator to configure VLANs on a single VTP server, easing the administration of a network. More ...
Wireless Standards - 802.11a 802.11b 802.11g 802.11n 802.11i Explained
The IEEE 802.11 family of standards which provides for Wireless Ethernet or (Wi-Fi) has evolved over the years. This article explains the differences between 802.11a 802.11b 802.11g 802.11n and 802.11i. More ...
Routing Information Protocol (RIP), Open Shortest Path First (OSPF), and Routing Convergence
A routing protocol advertises route information between routers. Dynamic routing protocols are available that allow a router's routing table to be updated as network conditions change. More ...
SYN-ACK Handshake to Establish a TCP Connection
TCP uses a SYN-ACK handshake to establish a connection. Three messages are required to establish a TCP connection between two hosts. More ...
X.25 and Frame Relay Overview
Frame Relay originated as an extension of integrated services digital network (ISDN). Its designers aimed to enable a packet-switched network to transport over circuit-switched technology. The technology has become a stand-alone and cost-effective means of creating a WAN. More ...
14 Common Network Ports You Should Know
Ports are virtual software-based and are managed by a computer's operating system. Different types of data flow to and from a computer over the same network connection. The use of ports informs computers what to do with the data they receive. Each port is assigned a number, and each is associated with a specific process or service. Port numbers are standardized, most reserved for certain protocols, for example, all HTTP messages go to port 80. More ...
Representation of IPv6 Addresses
IPv6 addresses are 128 bits in length and written as a string of hexadecimal digits. At first glance, these addresses can look overwhelming. RFC 2373 and RFC 5952 provide two helpful rules for reducing the notation involved in the standard format. 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 ...
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 ...
Shortest Path Bridging (SPB) Protocol
Shortest Path Bridging (SPB) protocol is a computer networking technology intended to simplify the creation and configuration of networks, while enabling multipath routing. It is the replacement for the older spanning tree protocols. More ...
