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 ...
Comparing IPv4 and IPv6 at a Glance
When examining the details of the IPv4 and IPv6 headers, there are some important differences between the two protocols. This article summarizes some of the differences. More ...
IGRP (Interior Gateway Routing Protocol)
IGRP (Interior Gateway Routing Protocol) is a routing protocol like RIP, however, it scales better than RIP because it uses a sophisticated metric based on bandwidth and delay, and has other advantages. More ...
PoE (Power Over Ethernet)
Say you want to mount a wireless access point (AP) on the ceiling. Although no electrical outlet is available, a switch feature called Power over Ethernet (PoE) IEEE 802.3at standard offers as much as 32.4W of power over a UTP cable. 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 ...
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 ...
NTP Server Systems - The Network Time Protocol
The Network Time Protocol (NTP) is utilized by NTP Server systems to distribute accurate time information to network time clients. The NTP protocol is widely used throughout the Internet to provide synchronization of computers and processes. This article discusses how NTP server systems utilize the Network Time Protocol to provide networks with an accurate reference of time. More ...
DSL (Digital Subscriber Line)
DSL (Digital Subscriber Line) is a technology used to transmit digital data over telephone lines. DSL service can be transmitted simultaneously with voice band telephone service on the same line because DSL uses a much higher frequency that rides on top of the low 3400 Hz voiceband. More ...
Network Routing Protocols - IGRP, EIGRP, OSPF, ISIS, BGP
The purpose of routing protocols is to learn of available routes on the network and make routing decisions. There are two primary routing protocol types; link state and distance vector. Some of the most common routing protocols include RIP, IGRP, EIGRP, OSPF, IS-IS and BGP. More ...
Free eBook: Introduction to 802.11 Wireless
The growth of wireless mobile devices is incredible. If you're an IT professional you'll need to understand wireless technology. This free ebook by Aaron Balchunas explains everything from radio frequency to wireless authentication protocols. More ...
IPv6 Packet Fragmentation
Unlike in IPv4, an IPv6 router does not fragment a packet unless it is the source of the packet. The fields used in the IPv4 header for fragmentation do not exist in the IPv6 header. More ...
Video - Data Link Layer of OSI Networking Model
In this video by Kevin Wallace you learn about the Data Link Layer of the OSI networking model. 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 ...
IPv6 Neighbor Discovery Protocol (NDP)
Neighbor Discovery Protocol (NDP) is used by IPv6 hosts for Router Discovery, Neighbor Discovery and Duplicate Address Discovery. 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 ...
