Networking Fundamentals​, Quick Notes – APPENDIX: Utilities & Services

WHOIS Tool

Output listing ownership of a domain name

TCPView

TCPView is a 3rd party GUI utility similar to NETSTAT.

Sample TCPVIEW Utility Output

Network Monitor

Network Monitor is a free utility, which can be used for learning a lot of things that happen behind the scenes. Though it may appear complicated initially, this tool can help in deeper understanding.

Sample: Connection Name “Wi-Fi” selected

  • Select “New Capture”
  • Select “Start”
  • Try PING or WHOIS command & Observe results under “Frame Summary”

Observe Process name, Source & Destination IP address, Protocol Used, etc.

TELNET SERVER (Microsoft Windows)

  • Control Panel > Programs & Features
  • Select “Turn Windows Features on or off”
  • Scroll and select “Telnet Server”, Select “OK”
  • START > RUN > SERVICES.MSC
  • Scroll and Select “Telnet”, Right-click & Select “Properties”
  • Select “Manual” from “Startup type:” dropdown, Select “Apply”
  • Select “Start” & Select “OK”
  • CMD > NET LOCALGROUP TelnetClients USERNAME/add 

Output listing command results; user accounts must be enabled for Telnet Access

TELNET CLIENT (Microsoft Windows)

  • Control Panel > Programs & Features
  • Select “Turn Windows Features on or off”
  • Scroll and select “Telnet Client”, Select “OK”
  • CMD > TELNET IPV4 Address

Connect to Telnet Service using an IPv4 address


Credentials

  • Specify Credentials as required

Output of a Telnet Connectivity

  • Open another CMD > NETSTAT -b

Observe Telnet Server Service available on Port 23

Note: Type “help | more” for commands supported under Telnet environment; Type “Exit” to quit.

HTTP + FTP Server – Internet Information Services (Microsoft Windows)

  • START > RUN > APPWIZ.CPL
  • Select “Turn Windows Features on or off”
  • Select “FTP Server”, “Web Management Tools” & “World Wide Web Services” & Select “OK”

Windows Features – Internet Information Services

  • Test for open port:
    • CMD > Telnet IPv4PORT (or) Telnet COMPUTERNAME PORT

Example: HTTP Service running on “LAB01” on Port “80”

  • A blank window with blinking cursor or custom message – confirms an open port at 80 (CTRL+C to stop)
  • Any other result – Port 80 is not open or blocked for response

Output when port is not open or blocked

Tip: Use Telnet to check Application Layer issues, such as if a remote service is enabled or having any connectivity issues such as firewall blocking a particular port.

  • Check Web Servers
    • CMD > Telnet DOMAINNAMEPORT# (Example: Telnet wikipedia.org 80)

Note: If SSL is available on a domain, then use Telnet domainname 443 (assuming default HTTPS port 443)

  • CMD > Telnet org 443

Example using wikipedia.org on port 443

  • To create FTP site (FTP sites are NOT created by default):
  • Control Panel> Administrative Tools > Internet Information Services (IIS) Manager
  • Right-click on Sites > Select “Add FTP Site…”

  • Create a folder, for example: C:\FTPDEMO
  • Specify a name for FTP site, for example: FTP DEMO& Select the folder created earlier

  • Select “Next”, Select “No SSL” and Select “Next”

  • Select “Anonymous” and “Basic” under Authentication
  • Select “All Users” under Allow access to:
  • Select “Read” under Permissions
  • Select “Finish”

Note: “Anonymous” access may be used where security is not a concern. Popular public ftp sites often provide access using Anonymous accounts.

  • To test FTP server:
    • CMD > Telnet COMPUTERNAME PORT#

Example: FTP Service running on “LAB01” on Port “21”

  • If FTP service is set to 8090 on domainname.extension, then:
  • CMD > Telnet domainname.extension 8090
  • To access FTP server:
    • CMD > ftp COMPUTERNAME

Example: Use “anonymous” as a valid User account (Windows) for credentials to log on

  • To view complete list of supported commands:
    • ftp > help

Output listing available commands

  • To access FTP service COMPUTERNAME on port 8090
    • CMD > ftp> open COMPUTERNAME 8090

Input to logon using different port number

  • To access FTP Service on domainname.extensionon port 8090,
    • CMD > ftp
    • open domainname.extension 8090

HTTP Server – WAMP (Windows Apache MySQL PHP in one)

Important: Use a different port for WAMP to avoid port conflict with IIS (if installed and working).

  • Install and launch the program
  • Open Web Browser > http://localhostor http://COMPUTERNAME

Important: If the web server is running on a different port (other than default port 80), then use http://COMPUTERNAME:PORT# (for example: http://LAB01:8080 (Colon format applicable for web browsers).

Apache Web Service listening on Port 8080

Note: Use TELNET to check for open ports.

 FTP Server – FileZilla

Administrative interface of Filezilla

  • Setup root directory
    • Select Add> Select a Folder (For example: C:\Tools)
  • Create FTP User Account
    • Edit > Users > Add(for example: Admin)
  • Test for open ports:
    • CMD > TELNET COMPUTERNAME 21

Example: FTP Service running on “LAB01” on Port “21”

  • To Connect to a FTP Server:
    • CMD > FTP COMPUTERNAME
    • Specify Credentials

Connected to an FTP Server, Directory Listing using DIR Command

Mail Server – HMAILSERVER

HMAILSERVER is a popular & powerful open source email server, suitable for home & small networks.

  • Download from https://www.hmailserver.com
  • Install and launch the program
  • Select Add domain…
  • Specify a domain name, for example: org
  • Select “Save”

Popup to connect in administrative mode

  • Test for open ports:
    • SMTP: CMD > Telnet COMPUTERNAME 25

Example: SMTP Service running on “LAB01” on Port “25”

  • POP3: CMD > Telnet COMPUTERNAME 110

Example: POP3 Service running on “LAB01” on Port “110”

  • IMAP: CMD > Telnet COMPUTERNAME 143

Example: IMAP Service running on “LAB01” on Port “143”

  • Check Mail Servers
  • SMTP: Telnet DOMAINNAME PORT (Example: Telnet mail.domainname.extension 25)
  • POP3: Telnet DOMAINNAME PORT (Example: Telnet mail.domainname.extension 110)
  • IMAP: Telnet DOMAINNAME PORT (Example: Telnet mail.domainname.extension 143)

Note: Output message might vary depending on respective server software; refer service provider website for exact port numbers as it usually varies (default ports may not respond if modified).

  • If POP3 service is set to 443 ondomainname.extension, then:
  • CMD > Telnet domainname.extension 443

Email Client – Thunderbird

Mozilla Thunderbird is an open source & free email client, suitable for home & office networks.

Create email accounts in HMAILSERVER

  • Launch HMAILSERVER Administrator
  • Expand domains, Select a domain
  • Right-Click Accounts, Select Add

  • Specify an account name (for example, user01), set a password & select “Save”

To view (or modify) port numbers for HMAILSERVER

  • Expand Domains, Expand Settings, Select TCP/IP Ports

HMAILSERVER Settings

Set up email account in Mozilla Thunderbird

  • Launch Mozilla Thunderbird
  • Select File > New > Existing Mail Account…

  • Enter Name, Email address& password, Select Continue
  • Select Manual Config

Mail settings

  • Specify settings as per server
  • Select “Done”

Note: Repeat the procedure to create & add multiple email accounts; specify computer name or IP address if setting up on LAN. Multiple email accounts can be setup on a single computer if required.

Wi-Fi Analyzers

Wireless Site Survey is a technique used for analyzing, planning & designing wireless networks; parameters such as speed, signal strength, etc. are used to estimate wireless equipment needs and placement of wireless access points.

Though technical expertise is required, there are simple tools available to get a high-level overview of current setup and modify the network setup if required (whether to use different channels, extend network by adding wireless extenders, etc.).

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