Home Office Network

Troubleshoot TCP/IP connectivity (check TCP and UDP port status)

Portqry.exe command-line utility:

Portqry.exe is a command-line utility that you can use to help troubleshoot TCP/IP connectivity issues.(check the TCP port status) Portqry.exe runs on Windows computers. The utility reports the port status of TCP and UDP ports on a computer that you select.

The port status is as following:

*Listening (open)

A process is listening on the port on the computer that you selected. Portqry.exe received a response from the port.
For example, you have web server is running on target computer, the web server is listing the TCP port 80.

*Not Listening (close)

No process is listening on the target port on the target system. Portqry.exe received an Internet Control Message Protocol (ICMP) “Destination Unreachable - Port Unreachable” message back from the target UDP port. Or if the target port is a TCP port, Portqry received a TCP acknowledgement packet with the Reset flag set.

*Filtered

The port on the computer that you selected is being filtered. Portqry.exe did not receive a response from the port. A process may or may not be listening on the port.

This utility also has a Windows application with GUI, which you can use easily without typing command line dos command.

The following shows the result to check the yahoo.com ’s web server port 80 status :

TCP/IP Network FAQ

PC to PC Data Transfer Device: (A Home Network Tool)

From time to time, we need to transfer Data from PC to PC. For example, you may want to transfer data from your old computer to a new computer. You may want to back up some data etc.

There are many ways to transfer data between PCs. (Within your home or office network)

(1) Use a USB flash drivers: You need to connect it to source computer, copy the files to USB flash Drivers, then connect it to target computer, and copy the file from USB flash to target computer. When you transfer big files, you need big capacity USB flash drivers, otherwise, you need to repeat this jobs many times.

(2)Use a USB external hard disk, You still need to connect it to source computer, copy file to external hard disk, then connect it to target computer and copy to target computers.

(3) If your computers are within same LAN (Home network), you can share the files of source computer, then copy these files to target computer.

and more….

Here is a PC to PC Data Transfer Device (Tornado) which made PC to PC file transfer very easy : ( With this device , my grandma can transfer data from PC to PC easily)

“PC to PC Data Transfer Device

Once connected to each PC, The Tornadoâ„¢ automatically displays the entire contents of each PC enabling the user to quickly drag-n-drop their files and file folders from one machine to the other. Operating at USB 2.0 speeds, The Tornadoâ„¢ moves files 600 % faster than standard flash memory-based storage media. The Tornadoâ„¢ is pocket-sized and has retractable cables allowing it to be easily carried anywhere.

Transfer Files between Any Windows® PCs

Built-in application (no software to install)

Backup your data at speeds up to 25Mb/Sec

Easiest way to migrate to a new computer

The easy to use graphical user interface autoloads by simply plugging the device into the USB port of each computer. The flashing LED light on the top of the device lights up to let you know that you’re connected. The entire contents of each PC are clearly displayed on the screens of BOTH COMPUTERS. Then you simply drag-n-drop files or entire directories from one machine to the other. It’s bi-directional so it doesn’t matter which machine you use to transfer the data. Just The Tornadoâ„¢!”

Home office network devices

Check TCP Port Status (Open or Closed)

Some times we need to check the TCP port status of a remote computer or network device/equipment.
for example, to see if a remote web server (port 80) is open, to see a remote H.323 VOIP gateway signalling port 1720 is open for you.
Here is a simple way to check the TCP port.
Telnet is a useful network command /tool which is built in with Windows 2000/XP/Vista

To check the TCP port status :
(1)Come to Command Prompt mode of your computer.
(2) Type: Telnet remote IP address or domain name Port number and hit enter. note: between IP address and port number, you need a space.
for exmple to check Yahoo.com’s web server :
telnet www.yaho.com 80
for exmple to check a remote voip gateway port 1720 status :
telnet xxx.xxx.xxx.xxx 1720
If the port is open, the screen will be cleared immediately and only the cursor is blinking on the screen.
if port is closed, it will show ” Connecting To www.yahoo.com” ,then show you ” Could not open a connection to host on port, Connect failed”

TCP Port Status (Hoe Network TCP Port numbers)

Serial to Ethernet :

Nowadays, we still have many legacy serial equipped machines in operations. How can we manage these devices remotely though Ethernet or Internet ? There are some network devices which allow you connect legacy serial equipped machines to your Ethernet LAN or WAN. Serial data from devices in the furthest corners of your plant show up on your office PC as if they were right next door. read more on Serial to Ethernet.

Network tools and devices

IP Network Tools and Commands

Metasploit Framework

The Metasploit Framework is a development platform for creating security tools and exploits. The framework is used by network security professionals to perform penetration tests, system administrators to verify patch installations, product vendors to perform regression testing, and security researchers world-wide.

Netcat

netcat is a computer networking utility for reading from and writing to network connections on either TCP or UDP.

Snort is a free software / open source network intrusion detection and prevention system capable of performing packet logging and real-time traffic analysis on IP networks. Snort was written by Martin Roesch but is now owned and developed by Sourcefire, of which Roesch is the founder and CTO. Proprietary versions with integrated hardware and support services are sold by Sourcefire.

Snort can perform protocol analysis, content searching/matching and can be used to detect a variety of attacks and probes, such as buffer overflows, stealth port scans, web application attacks, SMB probes, and OS fingerprinting attempts, amongst other features. The system can also be used for intrusion prevention purposes, by dropping attacks as they are taking place. Snort can be combined with other software such as SnortSnarf, sguil, OSSIM, and the Basic Analysis and Security Engine (BASE) to provide a visual representation of intrusion data. With patches for the snort source from Bleeding Edge Threats, support for packet stream antivirus scanning with ClamAV and network abnormality with SPADE, in the network layer 3 and 4, is possible with historical observation.

Wireshark

Wireshark is the world’s foremost network protocol analyzer ans it is free.

Features

Wireshark has a rich feature set which includes the following:

* Hundreds of protocols are supported, with more being added all the time
* Live capture and offline analysis
* Standard three-pane packet browser
* Multi-platform: Runs on Windows, Linux, OS X, Solaris, FreeBSD, NetBSD, and many others
* Captured network data can be browsed via a GUI, or via the TTY-mode TShark utility
* The most powerful display filters in the industry
* Rich VoIP analysis
* Read/write many different capture file formats: tcpdump (libpcap), Catapult DCT2000, Cisco Secure IDS iplog, Microsoft Network Monitor, Network General Sniffer® (compressed and uncompressed), Sniffer® Pro, and NetXray®, Network Instruments Observer, Novell LANalyzer, RADCOM WAN/LAN Analyzer, Shomiti/Finisar Surveyor, Tektronix K12xx, Visual Networks Visual UpTime, WildPackets EtherPeek/TokenPeek/AiroPeek, and many others
* Capture files compressed with gzip can be decompressed on the fly
* Live data can be read from Ethernet, IEEE 802.11, PPP/HDLC, ATM, Bluetooth, USB, Token Ring, Frame Relay, FDDI, and others (depending on your platfrom)
* Decryption support for many protocols, including IPsec, ISAKMP, Kerberos, SNMPv3, SSL/TLS, WEP, and WPA/WPA2
* Coloring rules can be applied to the packet list for quick, intuitive analysis
* Output can be exported to XML, PostScript®, CSV, or plain text

Also check Etheral

Telnet

TELNET is a network protocol used on the Internet or local area network (LAN) connections.
TELNET is a client-server protocol, based on a reliable connection-oriented transport. Typically this is TCP port 23.

Windows command line (DOS) Telnet utility
Command line usage : Telnet server name /IP address /port number

close close current connection
display display operating parameters
open connect to a site
quit exit telnet
set set options (type ’set ?’ for a list)
status print status information
unset unset options (type ‘unset ?’ for a list)
?/help print help information

For example, if you want to telnet to a host whose IP is xxx.xxx.xxx.xxx
From Windows : Start–>Run, then type telnet xxx.xxx.xxx.xxx and hit enter. this will take you to Telnet session.

1.Client: http://www.celestialsoftware.net/telnet/index.html
AbsoluteTelnet is a client for all versions of Windows, and includes telnet, SSH1, and SSH2.

2.Hyperterminal Private Edition is another Windows telnet client, free for personal use.
http://www.hilgraeve.com/htpe/index.html

3.mTelnet
is a free full-screen TELNET client for Windows & OS/2. Easy to use client with Zmodem download capability.
http://ozone.eesc.com/

Putty :Free client program for the SSH, Telnet and Rlogin network protocols

These protocols are all used to run a remote session on a computer, over a network. PuTTY implements the client end of that session: the end at which the session is displayed, rather than the end at which it runs.

In really simple terms: you run PuTTY on a Windows machine, and tell it to connect to (for example) a Unix machine. PuTTY opens a window. Then, anything you type into that window is sent straight to the Unix machine, and everything the Unix machine sends back is displayed in the window. So you can work on the Unix machine as if you were sitting at its console, while actually sitting somewhere else.

Download Putty and for more information on Putty

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TFTP

Trivial File Transfer Protocol (TFTP) is a very simple file transfer protocol, with the functionality of a very basic form of FTP; it was first defined in 1980.

Since it is so simple, it is easy to implement in a very small amount of memory — an important consideration at that time. TFTP was therefore useful for booting computers such as routers which did not have any data storage devices. It is still used to transfer small files between hosts on a network, such as when a remote X Window System terminal or any other thin client boots from a network host or server.

TFTP is based in part on the earlier protocol EFTP, which was part of the PUP protocol suite. In the early days of work on the TCP/IP protocol suite, TFTP was often the first protocol implemented on a new host type, because it was so simple.

TFTP uses UDP port 69 as its transport protocol ( FTP uses TCP port 21).

Windows TFTP command options:

Transfers files to and from a remote computer running the TFTP service.

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.

Free TFTP server Software :

1. 3Com TFTP/FTP
3CServer 1.1.007 - a TFTP and FTP server and client for Win32

2. SolarWinds TFTP Server
SolarWinds free TFTP Server is a multi-threaded TFTP server commonly used to upload and download executable images and configurations to routers and switches. The free TFTP Server runs on most Microsoft® operating system, including Windows® XP, Vista, 2000, and 2003.

3. Tftpd32

Tftpd32 includes DHCP, TFTP, SNTP and Syslog servers as well as a TFTP client.
The TFTP client and server are fully compatible with TFTP option support (tsize, blocksize and timeout), which allow the maximum performance when transferring the data.
Some extended features such as directory facility, security tuning, interface filtering; progress bars and early acknowledgments enhance usefulness and throughput of the TFTP protocol for both client and server.
The included DHCP server provides unlimited automatic or static IP address assignment.

4. Windows TFTP Utility
A Windows TFTP server and client written in the .NET framework using C#. Includes support for TFTP options, logging of TFTP requests to different sources including to a SQL server. A class is also available to include TFTP into your own program.

FTP or File Transfer Protocol is used to transfer data from one computer to another over the Internet, or through a network.

FTP is a commonly used protocol for exchanging files over any network that supports the TCP/IP protocol (such as the Internet or an intranet). There are two computers involved in an FTP transfer: a server and a client. The FTP server, running FTP server software, listens on the network for connection requests from other computers. The client computer, running FTP client software, initiates a connection to the server. Once connected, the client can do a number of file manipulation operations such as uploading files to the server, download files from the server, rename or delete files on the server and so on. Any software company or individual programmer is able to create FTP server or client software because the protocol is an open standard. Virtually every computer platform supports the FTP protocol. This allows any computer connected to a TCP/IP based network to manipulate files on another computer on that network regardless of which operating systems are involved (if the computers permit FTP access). There are many existing FTP client and server programs. FTP servers can be set up anywhere between game servers, voice servers, internet hosts, and other physical servers.

1. FTP command is DOS

from Windows: start–>run–>cmd come to Dos command line window.

To move a file from your computer to the server, type “put” and the file name. To get a file from the server and transfer to your computer, type “get” and the file name. When uploading /downloading many files to/from server, use “mput” and “mget”, You should use ascii when transferring text files, binary for executable files /binary files.
from DOS command line:
type : ftp host name/host IP address, then it prompts the user name and password, type user name and password.

FTP > put web.html
FTP > get myfile.txt
FTP > mput file1.html file2.html
FTP > mput *.txt
FTP > bin
FTP > put myimage.jpg
FTP > get myimage.jpg
FTP > mget *.gif

To get help , type ? or command ? (like ascii ?)

command options :
! 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

FTP Clients :

1. SmartFTP

SmartFTP is an FTP (File Transfer Protocol) client which allows you to transfer files between your local computer and a server on the Internet. With its many basic and advanced features SmartFTP also offers secure, reliable and efficient transfers that make it a powerful tool.

SmartFTP can be used for:

* Web site publishing and maintenance
* Upload and download of images, documents, movie and music files
* Share your files with your friends and coworkers
* Backups of local or remote files

2. Coreftp

CoreFTP

free Windows software that includes the client FTP features you need. Features like SFTP (SSH), SSL, TLS, IDN, browser integration, site to site transfers, FTP transfer resume, drag and drop support, file viewing & editing, firewall support, custom commands, FTP URL parsing, command line transfers, filters, and more.

3.CoffeeCup

CoffeeCup Free FTP is a fast no frills FTP program that makes it easy to drag and drop files to and from your Website. It supports multiple server profiles, resumes broken uploads and downloads, and can transfer files in binary, ASCII, or auto-mode. Free FTP works with any server and is so easy to setup. Just enter your username and password and click “Connect”.

Home Office Netcork Commands