The MicroTrain Blog

TCP/IP is today's most popular network protocol and is the protocol in the Internet. It is a routable protocol that provides connection between heterogeneous systems, these are the main reasons the protocol is so widely adapted; for example it allows communication between UNIX, Windows, Netware and Mac OS computers spread over multiple interconnected networks. The "TCP/IP protocol" is actually the "TCP/IP suite" composed of many different protocols each with its own functions. The two main protocols are in its name: the Internet Protocol and the Transmission Control Protocol.

IP addressing is assigning a 32-bit logical numeric address to a network device. Every IP address on the network must be unique. An IP address is represented in a dotted decimal format, for example: 159.101.6.8. As you can see the address is divided in 4 parts, these parts are called octets. The current used addressing schema in version 4 of IP is divided in 5 Classes:

TCP/IP Chart

A subnet mask is used to determine which part is the network part and which is the host part.
Default subnet masks

Class A     255.0.0.0
Class B     255.255.0.0
Class C     255.255.255.0

In a class A network, the first octet defines the network portion of the address. The last three octets are used for host addresses and subnet masking.

Network.Host.Host.Host
255.0.0.0

In a class B network, the first two octets define the network portion of the address. The last two octets are used for host addresses and subnet masking.

Network.Network.Host.Host
255.255.0.0

In a class C network, the first three octets define the network portion of the address. The last octet is used for host addresses and subnet masking.

Network.Network.Network.Host
255.255.255.0

A private network is one that will not be connecting directly to the Internet.  The term intranet is commonly use for this type of network.

The Internet Assigned Numbers Authority (IANA) has set aside the following IP address range for Intranet networks.

Private IP Address
IANA reserved 4 address ranges to be used in private networks; these addresses won't appear on the Internet avoiding IP address conflicts

10.0.0.0 through 10.255.255.255
172.16.0.0 through 172.31.255.255
192.168.0.0 through 192.168.255.255 

Special Addresses
Loopback Address                                127.0.0.1 (use for loopback test)

Destination                            Network                  Host

Host on this network              All zeroes               Host ID
Local Broadcast                    All ones                  All ones
Directed Broadcast                Network ID             All ones
Loopback Address                 127                       Anything

Automatic Private IP Addressing

(APIPA) is a feature of Windows-based operating systems that enables a computer to automatically assign itself an IP address when there is no Dynamic Host Configuration Protocol (DHCP) server available to perform that function. APIPA serves as a DHCP server failover mechanism and makes it easier to configure and support small local area networks (LANs).

169.254.0.0 - 169.254.255.255

If you have any questions please e-mail me at jescotal@microtrain.net

The Out of Office Assistant is a feature in Outlook that lets people know that you will be out of the office by sending and automatic reply to anyone sending you messages while you are gone.

This feature only works in Outlook if you are connected to an Exchange Server, which most companies use to manage email.

In Outlook 2003 and 2007 to use the feature, go to the Tools Menu, then click Out of Office Assistant.

Select the option: I am currently out of the office and then type a message in the box below. While activated, when people send you emails, they will automatically receive the AutoReply message, so be sure to let people know when you will be back or whom to contact while you are gone.

When you return to the office, make sure you turn the Out of Office Assistant off when you use Outlook again. Normally, Outlook will ask you to reset it back to "in the office" when you login to Outlook. If not, just go back to Tools > Out of Office Assistant and select, I am currently in the office.

That's it!