Just in Time Training

3 cruciale technologietrends

Je kunt je niet alleen maar richten op de veranderingen die op dit moment plaatsvinden. Richt je blik op de toekomst.

Technologie evolueert - en snel. Hoewel het misschien niet eenvoudig is om alles bij te houden kan je bedrijf het zich niet veroorloven om zich alleen te richten op de veranderingen die op dit moment plaatsvinden. Je moet verder kijken dan je neus lang is, naar de technologische trends die in opkomst zijn, zodat je de toekomst van je bedrijf en sector daarop kunt aanpassen. Waarom? Nou, hoe beter je kunt anticiperen op de techologie, hoe creatiever je deze kunt gebruiken om concurrentievoordeel te behalen.

Met 25 jaar ervaring met het accuraat voorspellen van de toekomst van de technologie, roep ik alle leidinggevenden op zich te richten op de volgende drie opkomende trends die flink verandering zullen brengen in het bedrijfslandschap zoals we dat nu kennen.

Innovatie zit in kleine dingen

Innovatie zit in de kleine dingen'

Dell staat te boek als slechts computerassembleerder die andermans tech goed gebruikt en zelf weinig bijdraagt. Maar innovatie is relatief én tegenwoordig anders, werpt de Chief Innovation Officer van Dell tegen. En dat geldt voor alle bedrijven.

Handige Windows Tools

5 gratis verdraaid handige Microsoft tools

Eigenlijk is het een treurig verhaal: de onlangs nog opgeleukte download portal van Microsoft bevat letterlijk tienduizenden programma's, maar buiten enkele bekende grote namen (zoals de Sysinternals tools van Mark Russinovich) krijgen ze nauwelijks de aandacht die ze verdienen. Toch zitten er echt juweeltjes verstopt tussen de duizenden whitepapers, beveiligingsupdates en een beerput aan PowerPoint presentaties.

Productivity Tips - Auto Hotkey

AutoHotKey for knowledge workers

For a good understanding  I recommend to watch  AutoHotKey episode published on YouTube. Below you can read the transcript of this episode.

Note the demonstrated TrackingNumber.AHK script can be downloaded here

Transcript AUTOHOTKEY for knowledge workers episode

[Start transcript]

Introduction

In episode one I demonstrated the use tracking numbers in a knowledge workers environment. Today I would like to tell you about a great software tool called AutoHotKey. AutoHotkey is a free, open source macro-creation and automation software utility which allows users to automate repetitive tasks. In this episode I will illustrate the use of AutoHotkey for the generation of tracking numbers and finding back documents tagged with these numbers.

Tracking number example

I will first show what kind of tasks we want to perform with AutoHotkey and then show how you can do it yourself. The principle of using tracking numbers in personal information management is simple:


you add a unique number to a document and store it where ever you want: either in your email environment or on your hard drive. When you want to retrieve the document you let your search engine look up the document using this number.

In this example email I ask for comments on of a draft report. To easily track responses I am going to add a tracking number that is composed of the year the month and the time I do this by typing in the code ‘tn’, short for tracking number. As you can see the code is directly replaced by the number generated by AutoHotKey.

Before I send this message I copy the subject and the tracking number. I will show you in a minute why I do this. Now I make sure that all documents related to this request like: the report, meeting notes and other correspondence have get this same number. Usually people reply to emails leaving in the original message and therefore also the tracking number.

You probably also have some system to keep track of all the requests you sent out. I have a simple excel file with action items and items I am waiting for. You can now paste the Subject and tracking number to the list. Here I use the clipboard manager built into office to retrieve the clipboard entries.

Retrieving documents

When you want to check the progress of this action you can easily find back all the related documents using a search engine. You could of course: start the search engine, copy the tracking number from the excel list, and then past it. But AutoHotkey can do that for you much faster and easier. In this case I have set up a AutoHotKey macro that is activate when I use the hotkey combination Windows-F8. As you can see the tracking number is automatically pasted in the search engine built into windows 7. And here are all the documents in outlook and my hard drive that contain the tracking number.



You can also add tracking numbers to single documents. If, for instance I want start reading this document I do not need to know where it is stored. I only have to select the tracking number press Windows F8 and I have it in seconds. For those who have seen the Pile-File episode may have noticed that I can also find a hardcopy of this document in my Pile-File under sequence number 397

Although there is no real hyperlink between the list and the referenced document using AutoHotKey it looks as if there is a virtual hyperlink.

You can also use this AutoHotkey macro for looking Words. If I for instance select the word Dayton and press Windows F8, I find all the documents on my computer with that word.

Setting up AutoHotKey

I will now show you how you can set up AutoHotkey to perform these activities: 

• First down load the free AutoHotkey from http://www.autohotkey.com/ and install it.
• Download the free trackingnumber.ahk script from my websitehttp://www.robsprotips.com 
• Activate the script by double clicking on it. 

You will see this Icon appearing in your task bar and know that it is running. Typing ‘tn’ will now generate a tracking number. And pressing windows-f8 will paste the selected number or word in the search engine.

The demonstrations here are given in Windows 7., This script will also work in Windows Vista. It also works in Windows XP with a separately installed: Windows Desktop Search.

• To make sure the script is active when you start up your computer you can do the following:  Make a shortcut for the script file
• Select the shortcut with the left mouse button and keep this button pressed while you browse via the Start button to the programs folder and to the startup folder.
• Drop the shortcut in the startup folder by releasing the left mouse button. From now on the script will automatically start.

How it works

AutoHotkey can do far more than the simple activities shown in this episode. If you have some programming experience I would certainly recommend exploring its possibilities. For those interested I will briefly show how the tracking number script works. But please do not panic if you do not understand. To use the script you do not need to understand how it works. If you open the script in notepad you will see the following lines:

• The lines beginning with a semicolon are comments and are ignored by the autohotkey.  These lines copy the selected tracking number (or text) and runs the search
• The hotkey “Windows - F8” is configured to launch the commands between the braces.
• The send command simulates the keystrokes: Control and C. This takes care of copying the selected text to the clipboard
• The second line runs the windows search engine taking the clipboard contents as input.
• ' Return' exits the script.

• These lines generate the tracking number based on date and time. (The letter ‘t and n’ are called an auto-replace hotstring because the typed characters are automatically erased and replaced by the number generated, by the following code. )
• This line creates a number based on the month, hour and minute, all without leading zero’s
• The send command sends the generated tracking number to the active window.
• The Return command exits the script. 

If you want to change the hotkey or autoreplace hotstring you can change windows-F8 or tn, save the file and double click on the file to reload the script.


I hope you have enjoyed this episode about AutoHotkey and tracking numbers for knowledge workers. Don’t forget to look at the other related video’s

This was Rob van den Akker, looking forward seeing you again with my next Episode.

[End transcript]

DNS

Domain Name System (DNS) servers maintain a distributed database used to translate computer names to Internet Protocol (IP) addresses on Transmission Control Protocol/Internet Protocol (TCP/IP) networks which includes the internet.

[NOTES FROM THE FIELD] - Being able to install DNS is not a requirement for the 70-270 exam. Understanding the functionality of DNS and how it affects Windows XP Professional clients in workgroups and within domains is.

In the next few weeks in my Learn Active Directory in 15 Minutes a Week series of articles I will cover DNS in more depth, including a more in depth view of installing DNS. 

The Microsoft Domain Name System (DNS) is the name resolution service that resolves Uniform Resource Locator names (URLs) and other DNS names into their “true” dotted decimal format. http://www.zandri.net translates into a specific Internet Protocol (IP) address and it is that address resolution that allows you to reach the server destination you are looking for.

Lookup Queries and Lookup Types
There are two different types of DNS lookup, forward and reverse. A forward lookup query resolves a DNS name to an IP address and is the most common DNS query. A reverse lookup query resolves an IP address to a name.

A DNS name server can resolve a query only for a zone for which it has authority. When DNS servers receive a resolution request, they attempt to locate the requested information in their own database.

There are two types of queries that can be performed in DNS: Iterative and Recursive.

A DNS resolution query made from a client to a DNS server where the server returns the best answer that it can provide based on its local cache or stored zone data is called an Iterative query. If the server performing the Iterative query does not have an exact match for the name request, it provides a pointer to an authoritative server in another level of the domain namespace. The client system will then query that server and so on and will continue this process until it locates a server that is authoritative for the requested name or until an error is returned such as name not found or a time-out condition is met.

A DNS resolution query made from a client to a DNS server in which the server assumes the full workload and responsibility for providing a complete answer to the query is called a recursive query.

The server, if it cannot resolve the resolution from it's own database will then perform separate iterative queries to other servers (on behalf of the client) to assist in returning an answer to the recursive query and will continue this process until it locates a server that is authoritative for the requested name or until an error is returned such as name not found or a time-out condition is met.

Client computers send recursive queries to DNS servers in most cases and usually the DNS server is set up to make iterative queries to provide an answer to the client.

The following is an example of the query process of a client computer making a request to a DNS server to resolve the address web address of www.zandri.net.

First the client computer generates a request for the IP address of www.zandri.net by sending a recursive query to the DNS server that it is configured to use in its network configuration. (We'll call this server LOCALCFG)

The second step is for LOCALCFG DNS server that has received a recursive query to look it its local database. If it does find that answer locally it is returned. If it is unable to locate an entry for www.zandri.net in its own database, it sends an iterative query to a DNS server that is authoritative for the root of the local domain. (We'll call this server LOCALROOT)

If the LOCALROOT DNS server, which is authoritative for the root domain, has the answer in its local database it sends a response to LOCALCFG. If the LOCALROOT DNS server is unable to locate an entry for www.zandri.net in its database, it sends a reply to the querying DNS server (LOCALCFG) with the IP addresses of DNS servers that are authoritative for the .net domain. (If it were .com you would be sent the IP addresses of DNS servers that are authoritative for the COM domain. If it were .org you would be sent the IP addresses of DNS servers that are authoritative for the ORG domain and so on.) We'll call this server DNSNET.

The DNS server that received the client recursive query (LOCALCFG) sends an iterative query to a server that is authoritative for the .net domain (DNSNET).

If the DNS server that is authoritative for the .net domain (DNSNET) has an entry for www.zandri.net in its local cache it will return it to LOCALCFG. If DNSNET is unable to locate an entry for www.zandri.net in its database, it sends a reply to the querying DNS server (LOCALCFG) with the IP addresses of DNS servers that are authoritative for the zandri.net domain. (We'll call this server ZANDRIDNS).

The DNS server that received the client recursive query (LOCALCFG) sends an iterative query to a server that is authoritative for the zandri.net domain. (ZANDRIDNS)

The DNS server that is authoritative for the zandri.net domain (ZANDRIDNS) locates an entry for www.zandri.net in its database and sends a reply to the querying DNS server (LOCALCFG) with the IP address of www.zandri.net.

The DNS server (LOCALCFG) that received the recursive query sends a reply to the client computer with the IP address of www.zandri.net.

If you have any questions, comments or even constructive criticism, please feel free to drop me a note.

I want to write solid technical articles that appeal to a large range of readers and skill levels and I can only be sure of that through your feedback.

Until next time, best of luck in your studies and remember,

"Clones are people two."a

TCP/IP troubleshooting

http://www.mcmcse.com/microsoft/guides/tcpip_troubleshooting.shtml


This article will continue with covering the TCP/IP Protocol within Windows XP Professional, specifically, troubleshooting of the network protocol under Windows XP Professional.

The Transmission Control Protocol/Internet Protocol is a network communication protocol. It can be used as a communications protocol on private networks and it is the default protocol in use on the internet. When you set up any system to have direct access to the Internet, whether it is via dial-up or one of the high speed technologies in use today, your system will need to utilize the TCP/IP protocol whether it is a Windows based system or not.

Also, if the given system needs to communicate to other TCP/IP systems on the local LAN or WAN it will need to utilize the TCP/IP protocol as well.

Windows XP Professional offers several native programs to use to help in troubleshooting TCP/IP.

PING - Ping can be used to test your TCP/IP connection by sending a message to the remote node or gateway from a local system. (It can also be used to test the loopback locally only to see if it is working correctly.) If the remote node or gateway receives the message, it responds with a reply message. The reply consists of the remote's IP address, the number of bytes in the message, how long it took to reply-given in milliseconds (ms), the length of time-to-live (TTL) in seconds and it will also show any pack loss in terms of percentages.

Pinging 127.0.0.1 with 32 bytes of data:

Reply from 127.0.0.1: bytes=32 time<1ms TTL=128
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128

Ping statistics for 127.0.0.1:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms

Usage: ping [-t] [-a] [-n count] [-l size] [-f] [-i TTL] [-v TOS]
[-r count] [-s count] [[-j host-list] | [-k host-list]]
[-w timeout] target_name

Switches:

• -t Ping the specified host until stopped. To see statistics and continue - type Control-Break; To stop - type Control-C.
• -a Resolve addresses to hostnames.
• -n count Number of echo requests to send.
• -l size Send buffer size.
• -f Set Don't Fragment flag in packet.
• -i TTL Time To Live.
• -v TOS Type Of Service.
• -r count Record route for count hops.
• -s count Timestamp for count hops.
• -j host-list Loose source route along host-list.
• -k host-list Strict source route along host-list.
• -w timeout Timeout in milliseconds to wait for each reply.

ARP - Displays and modifies the IP-to-Physical address translation tables used by
address resolution protocol (ARP).

ARP -s inet_addr eth_addr [if_addr]
ARP -d inet_addr [if_addr]
ARP -a [inet_addr] [-N if_addr]

• -a Displays current ARP entries by interrogating the current protocol data. If inet_addr is specified, the IP and Physical addresses for only the specified computer are displayed. If more than one network interface uses ARP, entries for each ARP table are displayed.
• -g Same as -a.
• inet_addr Specifies an internet address.
• -N if_addr Displays the ARP entries for the network interface specified by if_addr.
• -d Deletes the host specified by inet_addr. inet_addr may be wildcarded with * to delete all hosts.
• -s Adds the host and associates the Internet address inet_addr with the Physical address
• eth_addr. The Physical address is given as 6 hexadecimal bytes separated by hyphens. The entry is permanent.
• eth_addr Specifies a physical address.
• if_addr If present, this specifies the Internet address of the interface whose address translation table should be modified. If not present, the first applicable interface will be used.

Example:
> arp -s 157.55.85.212 00-aa-00-62-c6-09 .... Adds a static entry.
> arp -a .... Displays the arp table.

IPCONFIG - Use the ipconfig command to get the local system's basic IP configuration information, including the IP address, subnet mask, and default gateway.

The IPCONFIG/all switch produces a detailed configuration report for all interfaces, including any configured remote access adapters.

USAGE: ipconfig [/? | /all | /renew [adapter] | /release [adapter] | /flushdns | /displaydns | /registerdns | /showclassid adapter | /setclassid adapter [classid] ]

• /all Display full configuration information.
• /release Release the IP address for the specified adapter.
• /renew Renew the IP address for the specified adapter.
• /flushdns Purges the DNS Resolver cache.
• /registerdns Refreshes all DHCP leases and re-registers DNS names
• /displaydns Display the contents of the DNS Resolver Cache.
• /showclassid Displays all the dhcp class IDs allowed for adapter.
• /setclassid Modifies the dhcp class id.

The default is to display only the IP address, subnet mask and default gateway for each adapter bound to TCP/IP.

For Release and Renew, if no adapter name is specified, then the IP address leases for all adapters bound to TCP/IP will be released or renewed.

NBTSTAT - NetBT Statistics (Nbtstat.exe) is used for troubleshooting network NetBIOS names over TCP/IP (NetBT) resolution problems from the command line. It displays protocol statistics and current TCP/IP connections that are using NetBT.

When a network is functioning, NetBT resolves NetBIOS names to IP addresses. It uses several options for NetBIOS name resolution, including local cache lookup, WINS server query, broadcast, Lmhosts and Hosts file lookup, and DNS server query.

Displays protocol statistics and current TCP/IP connections using NBT
(NetBIOS over TCP/IP).

NBTSTAT [ [-a RemoteName] [-A IP address] [-c] [-n] [-r] [-R] [-RR] [-s] [-S] [interval] ]

• -a (adapter status) Lists the remote machine's name table given its name
• -A (Adapter status) Lists the remote machine's name table given its IP address.
• -c (cache)Lists NBT's cache of remote [machine] names and their IP addresses
• -n (names)Lists local NetBIOS names.
• -r (resolved) Lists names resolved by broadcast and via WINS
• -R (Reload) Purges and reloads the remote cache name table
• -S (Sessions) Lists sessions table with the destination IP addresses
• -s (sessions) Lists sessions table converting destination IP addresses to computer NETBIOS names.
• -RR(ReleaseRefresh) Sends Name Release packets to WINS and then, starts Refresh
• RemoteName - Remote host machine name.
• IP address - Dotted decimal representation of the IP address.
• interval - Redisplays selected statistics, pausing interval seconds between each display. Press Ctrl+C to stop redisplaying statistics.

NETSTAT - Netstat (Netstat.exe) displays TCP/IP protocol statistics and active connections to and from your computer from the command line and also provides an option to display the number of bytes sent and received, as well as network packets dropped (if any).

NETSTAT [-a] [-e] [-n] [-o] [-s] [-p proto] [-r] [interval]

• -a Displays all connections and listening ports.
• -e Displays Ethernet statistics. This may be combined with the -s option.
• -n Displays addresses and port numbers in numerical form.
• -o Displays the owning process ID associated with each connection.
• -p proto Shows connections for the protocol specified by proto; proto may be any of: TCP, UDP TCPv6, or UDPv6. If used with the –s option to display per-protocol statistics, proto may be any of: IP, IPv6, ICMP, ICMPv6, TCP, TCPv6, UDP, or UDPv6.
• -r Displays the routing table.
• -s Displays per-protocol statistics. By default, statistics are shown for IP, IPv6, ICMP, ICMPv6, TCP, TCPv6, UDP, and UDPv6; the -p option may be used to specify a subset of the default.
• interval Redisplays selected statistics, pausing interval seconds between each display. Press CTRL+C to stop redisplaying statistics. If omitted, netstat will print the current configuration information once.

ROUTE - You can use the route command line tool to display the current IP routing table and add or delete IP routes.

ROUTE [-f] [-p] [command] [destination] [MASK netmask] [gateway] [METRIC metric] [IF interface]

• -f Clears the routing tables of all gateway entries. If this is used in conjunction with one of the commands, the tables are cleared prior to running the command.
• -p When used with the ADD command, makes a route persistent across boots of the system. By default, routes are not preserved when the system is restarted. Ignored for all other commands, which always affect the appropriate persistent routes.

commands

• PRINT Prints a route
• ADD Adds a route
• DELETE Deletes a route
• CHANGE Modifies an existing route

• destination - Specifies the host.
• MASK -Specifies that the next parameter is the 'netmask' value.
• netmask - Specifies a subnet mask value for this route entry. If not specified, it defaults to 255.255.255.255.
• gateway - Specifies gateway.
• interface - Specifices the interface number for the specified route.
• METRIC - Specifies the metric, ie. cost for the destination.

All symbolic names used for destination are looked up in the network database file NETWORKS. The symbolic names for gateway are looked up in the host name database file HOSTS.

If the command is PRINT or DELETE. Destination or gateway can be a wildcard, (wildcard is specified as a star '*'), or the gateway argument may be omitted.

If Dest contains a * or ?, it is treated as a shell pattern, and only matching destination routes are printed. The '*' matches any string, and '?' matches any one char. Examples: 157.*.1, 157.*, 127.*, *224*.

Invalid MASK generates an error, that is when (DEST & MASK) != DEST.

Example> route ADD 157.0.0.0 MASK 155.0.0.0 157.55.80.1 IF 1 The route addition failed: The specified mask parameter is invalid. (Destination & Mask) != Destination.

Examples:

route PRINT
route ADD 157.0.0.0 MASK 255.0.0.0 157.55.80.1 METRIC 3 IF 2
      destination^            mask^    gateway^        metric^    ^Interface

If IF is not given, it tries to find the best interface for a given gateway.

route PRINT 112* .... Only prints those matching 112*
route CHANGE 112.0.0.0 MASK 255.0.0.0 112.89.8.5 METRIC 2 IF 2

CHANGE is used to modify gateway and/or metric only.

HOSTNAME - Hostname is used to show the local computer's host name for authentication by the Remote Copy Protocol (RCP), Remote Shell (RSH), and Remote Execution (REXEC) tools

TRACERT - Tracert is sometimes used to verify that IP addressing has been correctly configured on a client. It will basically show the route taken to reach a remote system

Usage: tracert [-d] [-h maximum_hops] [-j host-list] [-w timeout] target_name

Options:

• -d Do not resolve addresses to hostnames.
• -h maximum_hops Maximum number of hops to search for target.
• -j host-list Loose source route along host-list.
• -w timeout Wait timeout milliseconds for each reply.

PATHPING - Pathping also shows the route taken to reach a remote system as does TRACERT but PATHPING does so with more detail and allows for more functionality as well.

Usage: pathping [-g host-list] [-h maximum_hops] [-i address] [-n] [-p period] [-q num_queries] [-w timeout] [-P] [-R] [-T] [-4] [-6] target_name

Options:

• -g host-list Loose source route along host-list
• -h maximum_hops Maximum number of hops to search for target. 
• -i address Use the specified source address.
• -n Do not resolve addresses to hostnames.
• -p period Wait period milliseconds between pings.
• -q num_queries Number of queries per hop.
• -w timeout Wait timeout milliseconds for each reply.
• -P Test for RSVP PATH connectivity.
• -R Test if each hop is RSVP aware.
• -T Test connectivity to each hop with Layer-2 priority tags.
• -4 Force using IPv4.
• -6 Force using IPv6.

There are additional tools that can be used to test TCP/IP connectivity. They are standard use tools for the TCP/IP protocol.

FTP

- FTP is the File Transfer Protocol and it is used to transfer files from system to system.

Internet Explorer interconnectivity allows for a Windows Explorer type of GUI environment for the file transfer by allowing functionality of file and folder views and drag and drop / copy and paste.

The command line FTP allows for more functionality. FTP is considered to be a connected session using Transmission Control Protocol (TCP).

FTP commands are listed in the table below.

!	delete	literal	prompt	send
?	debug	ls	put	status
append	dir	mdelete	pwd	trace
ascii	disconnect	mdir	quit	type
bell	get	mget	quote	user
binary	glob	mkdir	recv	verbose
bye	hash	mls	remotehelp
cd	help	mput	rename
close	lcd	open	rmdir

FTP [-v] [-d] [-i] [-n] [-g] [-s:filename] [-a] [-w:windowsize] [-A] [host]

• -v Suppresses display of remote server responses.
• -n Suppresses auto-login upon initial connection.
• -i Turns off interactive prompting during multiple file transfers.
• -d Enables debugging.
• -g Disables filename globbing (see GLOB command).
• -s:filename - Specifies a text file containing FTP commands; the commands will automatically run after FTP starts.
• -a Use any local interface when binding data connection.
• -A - login as anonymous.
• -w:buffersize - Overrides the default transfer buffer size of 4096.
• host - Specifies the host name or IP address of the remote host to connect to.

[NOTES FROM THE FIELD] - Use mget and mput commands take y/n/q for yes/no/quit.
Use Control-C to abort actively executing commands.

TFTP - The Trivial File Transfer Protocol allows for the connectionless transfer of files to and from systems using User Datagram Protocol (UDP).

[NOTES FROM THE FIELD] - User Datagram Protocol (UDP) is a connectionless protocol that does not guarantee delivery of data packets between hosts and is used when data transfer acknowledgments are not required. It can transmit only small portions of data at a time because it is not capable of segmenting and reassembling frames and does not implement sequence numbers.

While TFTP is limited in functionality, there are still some command line switches that can be used to tailor its performance.

TFTP [-i] host [GET | PUT] source [destination]

• -i Specifies binary image transfer mode (also called octet). In binary image mode the file is moved literally, byte by byte. Use this mode when transferring binary files.
• host - Specifies the local or remote host.
• GET - Transfers the file destination on the remote host to the file source on the local host.
• PUT - Transfers the file source on the local host to the file destination on the remote host.
• source - Specifies the file to transfer.
• destination - Specifies where to transfer the file.

TELNET - Telnet is a terminal emulation program, which allows user to perform commands on a remote computer from a command window.

telnet [-a][-e escape char][-f log file][-l user][-t term][host [port]]

• -a Attempt automatic logon. Same as -l option except uses the currently logged on user's name.
• -e Escape character to enter telnet client prompt.
• -f File name for client side logging
• -l Specifies the user name to log in with on the remote system. Requires that the remote system support the TELNET ENVIRON option.
• -t Specifies terminal type. Supported term types are vt100, vt52, ansi and vtnt only.
• host - Specifies the hostname or IP address of the remote computer to connect to.
• port - Specifies a port number or service name.

RCP - RCP copies files to and from computer running the RCP service. RCP uses the Transmission Control Protocol (TCP) toutilize the connected and reliable delivery of data between the client and the host and can be scripted in a batch file and does not require a password. The remote host must be running the RSHD service, and the user’s username must be configured in the remote host’s .rhosts file. RCP is one of the r-commands available on all UNIX systems.

[NOTES FROM THE FIELD] - Microsoft’s implementation of TCP/IP includes the RCP client software but not rshd services.

RCP [-a | -b] [-h] [-r] [host][.user:]source [host][.user:] path\destination

• -a Specifies ASCII transfer mode. This mode converts the EOL characters to a carriage return for UNIX and a carriage return/line feed for personal computers. This is the default transfer mode.
• -b Specifies binary image transfer mode.
• -h Transfers hidden files.
• -r Copies the contents of all subdirectories; destination must be a directory.
• host Specifies the local or remote host. If host is specified as an IP address OR if host name contains dots, you must specify the user.
• .user: Specifies a user name to use, rather than the current user name.
• source Specifes the files to copy.
• path\destination Specifies the path relative to the logon directory on the remote host. Use the escape characters (\ , ", or ') in remote paths to use wildcard characters on the remote host.

RSH - RSH is a TCP/IP utility that enables clients to run commands directly on remote hosts running the RSH service without having to log on to the remote host. RSH is one of the UNIX r-commands that are available on all UNIX systems.

[NOTES FROM THE FIELD] - Microsoft’s implementation of TCP/IP includes the RSH client software but not the RSH service. If a user on a computer running in a Windows domain tries to use RSH to run a command on a remote UNIX server that is running the RSH daemon, the domain controller is required by the RSH client in order to resolve the username of the user.
REXEC - REXEC runs commands on remote hosts running the REXEC service and authenticates the user name on the remote host before executing the specified command.

REXEC host [-l username] [-n] command

• host Specifies the remote host on which to run command.
• -l username Specifies the user name on the remote host.
• -n Redirects the input of REXEC to NULL.
• command Specifies the command to run.

FINGER - FINGER is a TCP/IP utility used for viewing information about a user on a system running the finger service.

Typing the command finger jason@windowsxp.2000trainers.com displays information about user Jason on a server called windowsxp.2000trainers.com.

FINGER [-l] [user]@host [...]

• -l Displays information in long list format.
• user Specifies the user you want information about. Omit the user parameter to display information about all users on the specified host.
• @host Specifies the server on the remote system whose users you want information about.

[NOTES FROM THE FIELD] - Microsoft’s implementation of TCP/IP includes the FINGER client software but not the FINGER service. You are able to run the FINGER client on a machine running a Windows operating system that is connected to the Internet in order to obtain results from a remote UNIX server running the FINGER daemon as a FINGER gateway.

"I still yet have to figure out why they just don't make mouse-flavored cat food."

TCP/IP

This article will cover the TCP/IP Protocol within Windows XP Professional.

The Transmission Control Protocol/Internet Protocol is a network communication protocol. It can be used as a communications protocol on private networks and it is the default protocol in use on the internet. When you set up any system to have direct access to the Internet, whether it is via dial-up or one of the high speed technologies in use today, your system will need to utilize the TCP/IP protocol whether it is a Windows based system or not.

Also, if the given system needs to communicate to other TCP/IP systems on the local LAN or WAN it will need to utilize the TCP/IP protocol as well.

[NOTES FROM THE FIELD] - Indirectly connected computers, such as those on a LAN that hit the internet via certain default gateways, certain types of routers, Proxy Servers, ISA Servers or other indirect means, do not necessarily need to use the TCP/IP protocol. The need only use the network protocol in use for their LAN, where that LAN protocol would communicate with the directly connecting mechanism, (default gateway, router, Proxy Server or other direct device). That directly connected device would need to use the internet default protocol of TCP/IP.

TCP/IP is technically made up of two protocols. The upper layer, Transmission Control Protocol, on the sending system is responsible for breaking down the data into smaller packets to be transmitted over the network, (local and internet), while the TCP layer on the receiving node reassembles the packets it receives back into the original data structure.

The lower layer, Internet Protocol, addresses each individual packet so that it gets delivered to the correct node. Each routing device on the network, be it a hardware router or a server system that is performing routing functions, will check the destination address to see where to forward the message.

[NOTES FROM THE FIELD] - This is just a basic overview of TCP/IP and I didn't want to get too involved with it here within this article. There is bountiful information on TCP/IP all over the internet and before pouring through the RFCs I would first suggest you try TCP/IP Frequently Asked Questions.

The TCP/IP Model

The TCP/IP suite of protocols maps to a four-layer conceptual model which is based off of the seven layer Open System Interconnection (OSI) protocol model.

The detailed function of each layer of the Open System Interconnection (OSI) protocol model is beyond the scope of this topic, however, the 60 second overview is as follows:

Physical Layer - Defines the interface between the medium and the device. This layer also transmits bits (ones and zeros) and defines how the data is transmitted over the physical medium. Some examples of Network Components found at this layer are Multiplexers, Passive Hubs, Active Hubs, Repeaters and other types of signal Amplifiers.

Data Link Layer - This layer is actually divided into to sublayers, Logical Link Control, which mainly handles error correction and flow control and Media Access Control, which mainly handles the communication with the network adapter card. Some examples of Network Components found at the Data Link layer are Bridges, Switches and certain Advanced Cable Testers.

Network Layer - This OSI layer is responsible for translating logical network address and names such as computernames to their MAC addresses and for addressing and routing data packets over the network. If routers at this layer can’t forward the data frames as large as the source node has sent, this OSI layer will break down the data into smaller units that the devices can handle. Some examples of Protocols found at the Network Layer are IP, ARP, RARP, ICMP, RIP, OSFP, IGMP, IPX, NWLink and NetBEUI. Some examples of Network Components found at this layer are Brouters, Routers, some types of ATM Switches and Frame Relay hardware.

Transport Layer - The Transport Layer adds an additional connection below the Session layer and helps manage data flow control between nodes on the network. This layer divides the data into packets on the sending node and the transport layer of the receiving node reassembles the message from packets. The Transport Layer provides error-checking to guarantee error-free data delivery by requesting retransmission if some packets don’t arrive error-free. It also sends acknowledgment of successful transmissions back to the sending node. Some examples of Protocols found at this layer are TCP, ARP, RARP, SPX and NWLink. Some examples of Network Components found at the Transport Layer are Gateways and certain types of Brouters.

Session Layer - This OSI layer, as the name implies, establishes, maintains and ends sessions between transmitting nodes across the network and manages which node can transmit data at a certain time and for how long. Some examples of Protocols found at this layer are Names Pipes, NetBIOS Names, RPC and Mail Slots. Some examples of Network Components found at the Session Layer are Gateways and certain types of Proxy Servers.

Presentation Layer - The Presentation Layer technically performs the translation of the data from the way applications understand it to the way networks understand it on the transmission end and then back on the receiving node. It is responsible for protocol conversions, data encryption / decryption, and data compression / decompression where the network is considered. Some examples of Network Components found at the Presentation Layer are Gateways and certain types of Redirectors. There are no Protocols that normally operate in this layer.

Application - The Application Layer of the OSI model allows access to network services for applications specifically written to run over the network, such as email and file transfer programs such as FTP. There are many Protocols found at the Application Layer, some of which include FTP, TFTP, BOOTP, SNMP, SMTP, TELNET, NCP, and SMB.

The TCP/IP suite four-layer conceptual model is as follows;

Network Interface Layer - This layer effectively puts the frames on the wire from the sending node and pulls frames off the wire at the receiving node and basically correlates to the Physical Layer of the OSI model.

Internet Layer - Internet layer protocol of the TCP/IP suite encapsulate packets into Internet datagrams. There are four Internet protocols that operate at this layer. The Internet Layer basically (but not entirely) correlates to the Network Layer of the OSI model.

IP	Internet Protocol provides connectionless packet delivery for all other protocols and does not guarantee packet arrival or correct packet sequence nor does it acknowledge packet delivery. IP has the main responsibility of addressing and routing packets between nodes and it does not try to recover from network errors.
ARP	Address Resolution Protocol maps IP addresses to a physical machine addresses (MAC addresses) that are located on the LAN. IP broadcasts a special ARP inquiry packet containing the IP address of the destination system. The system that owns the IP address replies by sending its physical address to the requester. The MAC sublayer communicates directly with the network adapter card and is responsible for delivering error-free data between network.
ICMP	Internet Control Message Protocol is a message control and error-reporting protocol used between network nodes. Higher level protocols use the information in these datagrams to recover from any transmission or other errors.
IGMP	The Internet Group Management Protocol provides a way for nodes to report their multicast group membership to nearby multicast routers. Multicasting allows nodes to send content to multiple other nodes within that multicast group by sending IP multicast traffic to a single MAC address but by allowing it to be processed by multiple nodes. IGMP is part of the Network layer of the OSI model. Windows XP Professional supports multicast for things such as Windows 2000 Server NetShow Services.

Transport Layer - The two Transport layer protocols provide communication sessions between computers and these sessions can be connection oriented or connectionless, as outlined below. The Transport Layer basically (but not entirely) correlates to the Transport Layer of the OSI model.

TCP

Transmission Control Protocol is a connection-oriented protocol that provides reliable communication by assigning a sequence number to each segment of data that is transmitted so that the receiving host can send an acknowledgment (ACK) to verify that the data was received. If an ACK is not received, the data is retransmitted. TCP guarantees the delivery of packets, ensures proper sequencing of the data, and provides a checksum feature that validates both the packet header and its data for accuracy.

UDP

User Datagram Protocol is a connectionless protocol that does not guarantee the delivery or the correct sequencing of packets. Applications that use UDP typically transfer small amounts of data at once and the data sent is usually not considered critical. TFTP (Trivial File Transfer Protocol) uses UDP.

Application Layer - The Application Layer is where applications that are specifically written to operate over networks, gain their access. There are two TCP/IP services, Winsock and the NetBIOS over TCP/IP (NetBT) interface, that network applications most commonly use on Windows XP Professional networks. The Application Layer basically (but not entirely) correlates to the Application Layer of the OSI model.

Winsock

Winsock is the standard interface used for socket-based applications and TCP/IP protocols. Winsock allows the network application to bind to a specific port and IP address on a node, initiate and accept a connection, send and receive data, and close then close the connection.

NetBT

NetBIOS over TCP/IP is the standard interface for NetBIOS services, including name, datagram, and session services. It also provides a standard interface between NetBIOS-based applications and TCP/IP protocols and is the network component that performs computer name to IP address mapping name resolution. There are currently four NetBIOS over TCP/IP name resolution methods: b-node, p-node, m-node and h-node.

Internet Protocol Addressing Overview

The Transmission Control Protocol/Internet Protocol is a network communication protocol. It can be used as a communications protocol on private networks and it is the default protocol in use on the internet. When you set up any system to have direct access to the Internet, whether it is via dial-up or one of the high speed technologies in use today, your system will need to utilize the TCP/IP protocol whether it is a Windows based system or not.

Also, if the given system needs to communicate to other TCP/IP systems on the local LAN or WAN it will need to utilize the TCP/IP protocol as well.

TCP/IP version 4 (IPv4) addresses are made of up four 8-bit fields (octets) and are 32-bits in size total. Microsoft TCP/IP version 4 supports the standard classes of address, which defines which bits are used for the network ID and which bits are used for the host ID. There are five TCP/IP version 4 (IPv4) addresses, although for the most part, only the A, B, and C classes are used. The system of IP address classes described here form the basis for IP address assignment. Classless Inter-Domain Routing (CIDR) addressing is now being used more often and I will cover that later in the article. Classless Inter-Domain Routing is making the IP address classes in their current for "less defined", for lack of a better term. Still, the classes form the base of any addressing scheme.

TCP/IP version 4 address are made of both a network ID and a host ID. The network ID address identifies the physical network where the hosts exist. The host ID address identifies the individual TCP/IP host on a network. The host ID must be unique on the internal network, that is, no two nodes on a given network can have the same network ID AND host ID.

[NOTES FROM THE FIELD] - You can have two hosts with the IP host name of 112.12.44 if one is on network 10 and another is on network 11. (The full IP addresses of these hosts would be 10.112.12.44 and 11.112.12.44. The subnet mask would be 255.0.0.0.) You cannot assign both of these nodes the host address of 112.12.44 if they are both on network 10 or both on network 11.

The "division" point between the network ID and the host ID is called the subnet mask. The subnet mask is used to determine where the network number in an IP address ends and the node number in an IP address begins.

The bits in a subnet mask are set consecutively from left to right and there can be no "skips" in the setting structure. The subnet mask of 255.255.128.0 is valid because all eight bits are set in the first two octets and the first bit of the next octet is also set. (11111111.11111111.10000000.00000000). The subnet mask of 255.255.64.0 is not valid because there is a "missing" bit that is not allowed. (11111111.11111111.01000000.00000000).

[NOTES FROM THE FIELD] - The left most bit in a TCP/IP version 4 address is called the Most Significant Bit (MSB) and has the highest value. The right most bit in a TCP/IP version 4 address is called the Least Significant Bit (LSB) and has the lowest value.

I have detailed subnet masks in a little more detail in a following section. 

The value of the bits, in order from the Most Significant Bit (MSB) to the Least Significant Bit (LSB) are 128, 64, 32, 16, 8, 4, 2, 1. These numerical designations are what make up the TCP/IP version 4 address. Each set bit (noted by a "1") are added together to give you the address. The TCP/IP version 4 address of 171.144.62.12 converts to a binary number of 10101011.10010000.00111110.00001100 and a hexadecimal number of AB.90.3E.0C

[NOTES FROM THE FIELD] - While it's important to know that the TCP/IP version 4 address converts to a binary number or a hexadecimal number it is not often used in day to day operations of the MCSA/MCSE. It is more so for the Network Administrator. For the 70-270 exam, concentrate on the different classes of addresses, how subnet masks work, Classless Inter-Domain Routing (CIDR) addressing and a basic understanding of the binary conversion of a TCP/IP version 4 address. Basically, know the Most Significant Bit (MSB) and the Least Significant Bit (LSB) and the order of numbers. 

The way I remember it was to remember that the Least Significant Bit (LSB) of each octet was "1" and each place to the left of it doubled in value up to the end of the octet on the far left. After the DOT I would start back to "1"

TCP/IP version 6 (IPv6) addresses are a set of specifications from the Internet Engineering Task Force (IETF) and has been designed to overcome the current shortage of addresses under TCP/IP version 4. TCP/IP version 6 also has some other built in improvements that goes beyond the scope of the discussion here. The single most important thing you will need to know for the 70-270 exam (a little more depth may be needed for the upcoming Exam 70-275: Installing, Configuring and Administering Microsoft .NET Server and Exam 70-276: Implementing and Administering a Microsoft .NET Server Network Infrastructure) is that IPv6 addresses are 128 bits in length as opposed to 32 bits under IPv4.

Classless Inter-Domain Routing (CIDR) is a newer way to allocate IP addresses that is more flexible than with the original Class addressing scheme used in the past. This makes it so that the utilization of the number of remaining available Internet addresses has been increased. CIDR is now the routing system used by virtually all gateway hosts on the Internet's backbone network.

The original Internet Protocol defines IP addresses in five classes, Classes A through E. Each of these classes allowed the use of one portion of the 32-bit Internet address scheme to the network address and the remaining portion to the nodes on the network. One of the main reason for the IP address shortage was in the situation where many companies needed more than 254 host machines that were allowed under the Class C scheme but far fewer than the 65,533 host addresses of the Class B scheme. They would request a unique B Class address but often ended up not using many of the addresses within their allotted block. This meant that many addresses with their pool were unutilized. This is one of the main reasons the IP address pool was drying up and for this reason the big push was on for TCP/IP version 6 (IPv6) and its 128-bit address. Because many of the Internet authorities realized that it would be some time before IPv6 was in widespread use, Classless Inter-Domain Routing was born.

Using Classless Inter-Domain Routing, each IP address has a network prefix that identifies either a collection of network gateways or an individual gateway. The length of the network prefix is also specified as part of the IP address and varies depending on the number of bits that are needed (rather than any arbitrary class assignment structure). A destination IP address or route that describes many possible destinations has a shorter prefix and is said to be less specific. A longer prefix describes a destination gateway more specifically. Routers are required to use the most specific or longest network prefix in the routing table when forwarding packets.

A Classless Inter-Domain Routing network address looks like this: 201.44.112.00/18

201.44.112.00 is the address of the network and the "18" says that the first 18 bits are the network part of the address, leaving the last 14 bits for the address of the node. (Effectively, the 18 is the subnet mask from the "old" style of address classes.) Classless Inter-Domain Routing lets one routing table entry represent a collection of networks that exist in the forward path that don't need to be specified on that particular gateway. This collecting of networks in a single address is sometimes referred to as a supernet as by their definition they mean the same thing.

Classless Inter-Domain Routing is supported by The Border Gateway Protocol, the prevailing exterior (interdomain) gateway protocol. (The older exterior or interdomain gateway protocols, Exterior Gateway Protocol and Routing Information Protocol, do not support Classless Inter-Domain Routing.) Classless Inter-Domain Routing is also supported by the OSPF interior or intradomain gateway protocol.

Subnet Masks - Implementing subnewtorks (commonly referred to as subnets in the field) helps to control network traffic. Every node on the same physical Ethernet network sees all the packets of data sent out on the network. Often this has the result of multiple collisions causing network performance to be slow. Routers or gateways are used to separate networks into subnets. Subnet masks on each of the nodes allow the nodes on the same subnetwork to continue to communicate with one another and to the routers or gateways they use to send their messages.

Subnet masks allows you to identify the network ID and the host (node) ID of an IP address.

Given the following example of a default B Class subnet mask:

10011110.00010101.00111001.01101111 158.21.57.111
11111111.11111111.00000000.00000000 255.255.000.000
--------------------------------------------------------
10010110.11010111.00000000.00000000 158.21.000.000

we can determine that the network ID is 158.21 and the host ID is 57.111

Network Address : 158.21.0.0

Subnet Address : 158.21.0.0
Subnet Mask : 255.255.0.0
Subnet bit mask : nnnnnnnn.nnnnnnnn.hhhhhhhh.hhhhhhhh
Subnet Bits : 16
Host Bits : 16
Possible Number of Subnets : 1
Hosts per Subnet : 65534

Additional bits can be added to the subnet mask for a given class of addresses to subnet networks further.

Given the following example of a B Class address using an additional bit subnet mask:

10011110.00010101.00111001.01101111 158.21.57.111
11111111.11111111.11110000.00000000 255.255.240.000 Subnet Mask
--------------------------------------------------------
10010110.11010111.00010000.00000000 150.215.016.000 Network address

Subnet Mask : 255.255.240.0
Subnet bit mask : nnnnnnnn.nnnnnnnn.nnnnhhhh.hhhhhhhh
Subnet Bits : 20
Host Bits : 12
Possible Number of Subnets : 16
Hosts per Subnet : 4094

we can see that rather than having the single subnet and 65534 Hosts per Subnet allowed under the default subnet mask we are able to have up to 16 subnets with up to 4094 Hosts per Subnet by using a Subnet Mask of 255.255.240.000.

Selected Subnet : 158.21.0.0/255.255.240.0
Usable Addresses : 4094
Host range : 158.21.0.1 to 158.21.15.254
Broadcast : 158.21.15.255

Subnet	Mask	Subnets	Host Range	Broadcast
158.21.0.0	255.255.240.0	4094	158.21.0.1 to 158.21.15.254	158.21.15.255
158.21.16.0	255.255.240.0	4094	158.21.16.1 to 158.21.31.254	158.21.31.255
158.21.32.0	255.255.240.0	4094	158.21.32.1 to 158.21.47.254	158.21.47.255
158.21.48.0	255.255.240.0	4094	158.21.48.1 to 158.21.63.254	158.21.63.255
158.21.64.0	255.255.240.0	4094	158.21.64.1 to 158.21.79.254	158.21.79.255
158.21.80.0	255.255.240.0	4094	158.21.80.1 to 158.21.95.254	158.21.95.255
158.21.96.0	255.255.240.0	4094	158.21.96.1 to 158.21.111.254	158.21.111.255
158.21.112.0	255.255.240.0	4094	158.21.112.1 to 158.21.127.254	158.21.127.255
158.21.128.0	255.255.240.0	4094	158.21.128.1 to 158.21.143.254	158.21.143.255
158.21.144.0	255.255.240.0	4094	158.21.144.1 to 158.21.159.254	158.21.159.255
158.21.160.0	255.255.240.0	4094	158.21.160.1 to 158.21.175.254	158.21.175.255
158.21.176.0	255.255.240.0	4094	158.21.176.1 to 158.21.191.254	158.21.191.255
158.21.192.0	255.255.240.0	4094	158.21.192.1 to 158.21.207.254	158.21.207.255
158.21.208.0	255.255.240.0	4094	158.21.208.1 to 158.21.223.254	158.21.223.255
158.21.224.0	255.255.240.0	4094	158.21.224.1 to 158.21.239.254	158.21.239.255
158.21.240.0	255.255.240.0	4094	158.21.240.1 to 158.21.255.254	158.21.255.255

[NOTES FROM THE FIELD] - A subnet address cannot be all 0's or all 1's.

TCP/IP Class A Address Overview

The "A" class addressing scheme has an official start address of 0.0.0.0 and an official last address of 127.255.255.255.

Not all of these address can be used and you will OFTEN see conflicting information on this.

1.0.0.1 to 126.255.255.254 is the range of IP addresses that are included in the "A" class addressing scheme that are the useable range for node assignment

126.255.255.255 is a broadcast address and in most case cannot be assigned. (There are exceptions to the rule.)

The local host will use 0.0.0.0 when it cannot reach a DHCP server when it is set to use one and cannot assign itself an address using APIPA.

1.0.0.1 to 126.255.255.254 is the useable range.

There are 126 Class A networks total, each allowed to have up to 16,777,214 hosts

The 127.x.x.x range is used for internal host loopback

There are three IP network addresses reserved for private networks. 10.0.0.0 - 10.255.255.255 with the subnet mask 255.0.0.0 is the range for Class A IP addresses.

They can be used by anyone setting up internal IP networks, such as a lab or home LAN behind a NAT or proxy server or a router. It is always safe to use these because routers on the Internet will never forward packets coming from these addresses.

These addresses are defined in RFC 1918.

While 10.0.0.0 - 10.255.255.255 addresses with the subnet mask 255.0.0.0 are available to only internal IP networks, they are still considered part of the Class "A" range.

TCP/IP Class B Address Overview

The "B" class addressing scheme has an official start address of 128.0.0.0 and an official last address of 191.255.255.255.

Not all of these address can be used and you will OFTEN see conflicting information on this.

128.0.0.1 to 191.255.255.254 is the range of IP addresses that are included in the "B" class addressing scheme that are the useable range for node assignment.

The local host will use 0.0.0.0 when it cannot reach a DHCP server when it is set to use one and cannot assign itself an address using APIPA.

There are three IP network addresses reserved for private networks. 172.16.0.0 - 172.31.255.255 with the subnet mask 255.240.0.0 is the range for Class B IP addresses.

They can be used by anyone setting up internal IP networks, such as a lab or home LAN behind a NAT or proxy server or a router. It is always safe to use these because routers on the Internet will never forward packets coming from these addresses.

These addresses are defined in RFC 1918.

While 172.16.0.0 - 172.31.255.255 addresses with the subnet mask 255.240.0.0 are available to only internal IP networks, they are still considered part of the Class "B" range.

TCP/IP Class C Address Overview

The "C" class addressing scheme has an official start address of 192.0.0.0 and an official last address of 223.255.255.255.

Not all of these address can be used and you will OFTEN see conflicting information on this.

192.0.0.1 to 223.255.255.254 is the range of IP addresses that are included in the "C" class addressing scheme that are the useable range for node assignment.

The local host will use 0.0.0.0 when it cannot reach a DHCP server when it is set to use one and cannot assign itself an address using APIPA.

There are three IP network addresses reserved for private networks. 192.168.0.0 - 192.168.255.255 with the subnet mask 255.255.0.0 is the range for Class C IP addresses.

They can be used by anyone setting up internal IP networks, such as a lab or home LAN behind a NAT or proxy server or a router. It is always safe to use these because routers on the Internet will never forward packets coming from these addresses.

These addresses are defined in RFC 1918.

While 192.168.0.0 - 192.168.255.255 addresses with the subnet mask 255.255.0.0 are available to only internal IP networks, they are still considered part of the Class "C" range.

TCP/IP Class D Address Overview

The IP version 4 addresses of 224.0.0.0 through 239.255.255.255 are set aside through IANA (Internet Assigned Numbers Authority) as a special class of addresses for Multicast uses. At the present, ISPs are unable to allocate Class D address space to their customers. These addresses must be allocated through IANA.

Class D addresses are only required if you wish to be a multicast source. You can still receive multicast data without the need for a separate Class D address.

TCP/IP Class E Address Overview

The IP version 4 addresses of 240.0.0.0 to 254.255.255.255 are set aside through IANA (Internet Assigned Numbers Authority) as a special class of addresses for experimental and future use.

The IP address of 255.255.255.255 broadcasts to all hosts on the local network and therefore, is not to be considered as part of the E class of IP addresses.

"The fact that the grass is greener on the other side of the fence is directly proportional to how much manure is being used on the property"