Networking Routing Believability and Administrative Distance
If a network is running more than one routing protocol and a router receives two route advertisements from different routing protocols, which route advertisement does the router believe?. More ...
The OSI Physical Layer
The Physical layer (OSI layer 1) deals with the mechanical and electrical specifications of the network hardware. Layer 1 specifications define connectors, pin-outs, signal voltages, and related software. 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 ...
Major Protocols in the TCP/IP Suite
This is a chart of the layers of the TCP/IP Suite and the major protocols in each layer. As you move your mouse pointer over each protocol acronym, a brief description of the protocol appears. This is not a comprehensive list. More ...
Classless IP Addressing
In the beginning, classful addressing was a great idea for keeping IP addresses organized. But as the Internet grew, and IP addresses became scarce, classful addressing was found to be too limiting. Classless IP addressing, known as Inter-Domain Routing (CIDR) was released in September 1993. More ...
Video - Transport Layer (Layer 4) of OSI Networking Model
In this video by Kevin Wallace you learn about the Transport Layer of the OSI networking model. More ...
Pv6 Myths
There are several misperceptions or myths regarding IPv6. IPv6 has been around quite some time, initially introduced in 1995 with RFC 1883 and later obsoleted with RFC 2460 in 1998. Over the years, as IPv6 evolved and as people discussed the merits of the new protocol, certain misconceptions ensued. More ...
Unicast, Multicast, Broadcast. What Does It Mean?
Unicast, Multicast, and Broadcast are different network transmission methods. Unicast is a transmission between a single sender and a single receiver, while Broadcast is a transmission from a single sender to all clients on the network. 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 ...
What Are Private IP Addresses?
Normally you have to be assigned an IP address, or a group of IP addresses by a Regional Internet Registry. However, if you just need IP addresses for an internal network that will not be routed to the Internet, you can select from blocks of IP addresses reserved as Private IP addresses. More ...
Networking and Internet Standards Organizations
Without standards, the Internet would be chaos. The primary organization that sets communications standards for the Internet is the Internet Engineering Task Force (IETF). 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 ...
Looking at the OSI 7 Layer Reference Model
The OSI (Open Systems Interconnection) model is a 7 layer reference model for how applications can communicate over a network. Don't confuse The OSI model with TCP/IP Protocol which has 4 layers and is the actual architecture used for networking. More ...
TCP/IP Protocol Suite
A good portion of the knowledge required to be a network technician relates to the TCP/IP protocol suite. This article describes the most important protocols in the TCP/IP protocol suite. Many other less frequently used protocols exist. More ...
Link Aggregation
If all ports on a switch are operating at the same speed, the ports most likely to experience congestion are ports connecting to another switch or router. To help alleviate congested links between switches, you can logically combine multiple physical connections into a single logical connection. More ...
