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If All Ports Are Blocked
When ALL PORTS ARE BLOCKED, This typically means that you are conneted to the Internet through a Proxy, NAT (Network Address Translator) or Firewall Server.  If you are the Administrator of the Firewall/Proxy or NAT Server, you can open selective ports that you want redirected or forwarded to specific machines or hosts.  If you are not the administrator, you should contact your ISP or Systems Administrator for your local connection and find out if you are behind a Proxy/Firewall or NAT.

If All Ports Are Open
It's good for hosting, but bad for security.  In order to control intrusions, it's good to only open ports that you need.  Many firewalls, Proxy and NAT servers will automatically block all or most ports and only open the ones you force.  If all ports are open, you can install your own proxy, NAT or firewall, or you can make sure that the services that you do enable are secured with good passwords.  You can run almost any service you want if all your ports are open.  To get your own domain name for hosting on your home computer, go to http://www.tzo.com


Alternate WebServer Port 81
When a user types in your IP address or Host Name in their browser, the browser will look at the IP address on port 80 by default for the web pages.
Port 81 is used as an alternate web hosting port if your ISP blocks port 80.

Blocked - If this port is blocked, you can use the HTTP Port Relay Service from http://www.tzo.com to host your website on another port and get it redirected

Open - Ready to host your own Website.  Run Apache, TZO Web Server, or Microsoft IIS/Personal WebServer and you instantly have your own WebSite! Make sure you set the server to use port 81 if port 80 is blocked.

In Use - Either your PC is already running a Web or other server on port 81, or the NAT/Firewall that you are behind has a WebServer running already on port 81


WebServer Port 80
When a user types in your IP address or Host Name in their browser, the browser will look at the IP address on port 80 by default for the web pages.


Blocked - If this port is blocked, you can use the HTTP Relay Service from http://www.tzo.com to host your website on another port and get it redirected

Open - Ready to host your own Website.  Run Apache, Xitami or Microsoft IIS/Personal WebServer and you instantly have your own WebSite!

In Use - Either your PC is already running a Web Server, or the NAT/Firewall that you are behind has a WebServer running already


SSH Secure Shell Port 22
If you run a Secure Shell, this port is required for the SSH Client to connect to your server. SSH is used for remote shell access and in order to use SSH, port 22 must be open.

Blocked - If this port is blocked, there are typically no means of getting around a Telnet Block.  You will NOT be able to host remote telnet sessions unless your Telnet server can be set to another port.

Open - Ready to host your SSH sessions.  Run the SSH and you instantly have access your own server!

In Use - Either your PC is already running SSH



FTP Server Port 21
When someone attempts to connect to your FTP Server, the FTP client will attempt the connection on Port 21 by default. Port 21 must be open for standard FTP clients to log in and connect to your server.


Blocked - If this port is blocked, you can reference the file via HTTP so people can download, or you can create a directory on your website called "download" and place the file there. People should be able to download using a browser instead of an FTP Client.
There are typically no means of getting around an FTP Block

Open - Ready to host your own FTP site.  Run WarFTP or another shareware FTP Server and you instantly have your own FTP Site!

In Use - Either your PC is already running a FTP Server, or the NAT/Firewall that you are behind has a FTP Server running already


Telnet Server Port 23
If you run a Telnet server, this port is required for the Telnet Client to connect to your server. Telnet can be used for other ports to check services, but in order to use telnet for remote admin and login, port 23 must be open.

Blocked - If this port is blocked, there are typically no means of getting around a Telnet Block.  You will NOT be able to host remote telnet sessions unless your Telnet server can be set to another port.

Open - Ready to host your Telnet sessions.  Run the Telnet Server and you instantly have access your own server!

In Use - Either your PC is already running a Telnet Server, or the NAT/Firewall that you are behind has a Telnet Server running already


SMTP Server Port 25
When someone sends a mail message to your SMTP Server, the mail will attempt to come in to your server on Port 25. This is the standard SMTP (Simple Mail Transport protocol) that accepts email to your mail server.


Blocked - If this port is blocked, you can use the SMTP Store and Forward Service from http://www.tzo.com to host your SMTP Mail Server on any another port and get mail redirected to the port you specify.  It offers backup Mail Protection is your mail server goes down

Open - Ready to host your own Mail Server.  Run Argosoft Mail server, Lotus Notes or Microsoft Exchange Server and you instantly have your own Mail Server!  You can now give out your own Mail Accounts, Mailing Lists, and More!

In Use - Either your PC is already running a Mail Server on port 25, or the NAT/Firewall that you are behind has a  Mail Server running already on that port.


POP Server Port 110
When you run a mail server computer, users will typically log into that machine via POP3 (Post Office Protocol) or IMAP4 (Internet Message Access Protocol) to retrieve their mail. POP3 is the most popular protocol for accessing mailboxes.


Blocked - If this port is blocked, there are typically no means of getting around a POP3 Block, other than running IMAP4.  You will NOT be able to host a mail server using POP.

Open - Ready to host your Mail Server POP sessions.  Run the Mail POP Server and you instantly have access your own Mailbox via POP3

In Use - Either your PC is already running a POP Server, or the NAT/Firewall that you are behind has a POP Server running already


News (NNTP) Server Port 119
When you run a News server, typically News Clients wanting to connect to your news server will connect on port 119. This port needs to be open to run your own news server.


Blocked - If this port is blocked, there are typically no means of getting around this type of block.  You will NOT be able to host a news server for others.

Open - Ready to host your own News Server.  Run the News Server and select your News feeds from a provider. 

In Use - Either your PC is already running a News Server, or the NAT/Firewall that you are behind has a News Server running already


Netbios over TCP/IP Port 137-139
When you run Microsoft File and Print Sharing, these connections take place over these ports 137-139. Most ISP, Cable and DSL companies will block these ports due to security reasons. If these Ports are open, you can usually share files and printers over the Internet.


Blocked - If this port is blocked, there are typically no means of getting around it.  You will NOT be able to use Microsoft file and print sharing with others beyond your ISP.

Open - Ready to use MS file and print sessions.  Turn on File and Print sharing, and others should be able to access your Files or Printers!

In Use - Either your PC is already using Microsoft File and Print Services, or the NAT/Firewall that you are behind has a File and Print Session already in use.


LDAP Server Port 389
LDAP or Lightweight Directory Access Protocol is becoming popular for Directory access, or Name, Telephone, Address directories. For Example LDAP://LDAP.Bigfoot.Com is a LDAP directory server.


Blocked - If this port is blocked, there are typically no means of getting around a LDAP Block.  You will NOT be able to host remote LDAP sessions.

Open - Ready to host your own LDAP Server.  Run the Server and you instantly have access your own Directory Server!

In Use - Either your PC is already running a LDAP Server, or the NAT/Firewall that you are behind has a LDAP Server running already


IMAP4 Server Port 143
IMAP4 or Internet Message Access Protocol is becoming more popular and is used to retrieve Internet Mail from a remote server. It is more disk intensive, since all messages are stored on the server, but it allows for easy online, offline and disconnected use.


Blocked - If this port is blocked, there are typically no means of getting around it. By default, IMAP4 Clients will look on port 143 for your IMAP Server.  You will NOT be able to host an IMAP4 Server.

Open - Ready to host your IMAP4 Server.  Run the Server and you instantly have access your own Mailboxes on your Email server!

In Use - Either your PC is already running a IMAP4 Server, or the NAT/Firewall that you are behind has a IMAP4 Server running already


Secure Sockets Layer (SSL) Server Port 443
When you run a secure server, SSL Clients wanting to connect to your Secure server will connect on port 443. This port needs to be open to run your own Secure Transaction server.


Blocked - If this port is blocked, there are typically no means of getting around a SSL Block.  You will NOT be able to host secure sessions.

Open - Ready to host your own Secure Server.  Get your Secure Certificate from a CA (Certificate Authority), then simply run the Secure Server and you can start offering secure transactions.

In Use - Either your PC is already running a secure Server, or the NAT/Firewall that you are behind has a secure Server running already.


Alternate SMTP Port 2525
When someone sends a mail message to your SMTP Server, the mail will attempt to come in to your server on Port 25. Port 2525 is the Alternate SMTP port if your incoming port 25 is blocked by your ISP.


Blocked - If this port is blocked, you can use the SMTP Store and Forward Service from http://www.tzo.com to host your SMTP Mail Server on any another port and get mail redirected to the port you specify.  It offers backup Mail Protection is your mail server goes down

Open - Ready to host your own Mail Server.  Run Argosoft Mail server, Lotus Notes or Microsoft Exchange Server and you instantly have your own Mail Server!  Just make sure you set the SMTP port to 2525. You can now give out your own Mail Accounts, Mailing Lists, and More!

In Use - Either your PC is already running a Mail Server on port 2525, or the NAT/Firewall that you are behind has a  Mail Server running already on that port.


PCAnywhere Port 5631
When a PCAnywhere server is set up to receive remote requests, it listens on TCP port 5631. This allow you to run a PCAnywhere host and use the Internet to connect back and remotely control your PC.


Blocked - If this port is blocked, there are other means of getting around it.  Symantec has give users the option of changing the server and client to listen and connect on an alternate port. For more information, see the symantec website at http://www.symantec.com

Open - Ready to host your remote PC Anywhere sessions.  Run the PCAnywhere Host Server and you instantly have remote access your own server!

In Use - Either your PC is already running a PCAnywhere Host, or the NAT/Firewall that you are behind has a PCAnywhere Host Server running already.


Microsoft NetMeeting & VOIP Ports 1503 and 1720
MS NetMeeting and VOIP allows you to host an Internet VideoConference with other NetMeeting or VOIP users. NetMeeting is a free product that can be found on the Microsoft Website at http://www.microsoft.com/Netmeeting/


Blocked - If these ports are blocked, there are typically no means of getting around it.  You will NOT be able to host remote NetMeeting sessions.(This means you can all out, but people can't call you)

Open - Ready to host your VOIP or NetMeeting VideoConference sessions.  Run the NetMeeting or VOIP service and Host a call!

In Use - Either your PC is already running NetMeeting, or the NAT/Firewall that you are behind has a NetMeeting, VOIP or H.323 Gateway running already



Microsoft Remote Desktop Port 3389
When you want to remotely control a PC, Microsoft remote destop is is a free network remote control utility that comes bundled with Windows XP. Remote Desktop accepts incoming connections on port 3389

Blocked - If this port is blocked, You will NOT be able to host remote desktop remote control sessions unless your Remote desktop server can be set to listen to another port.Typically remote desktop runs on port 3389

Open - Ready to host your remote desktop remote control sessions.  Run the Remote desktop Server and you and others instantly have access to remotely control your own server remotely! More Info on running your own Remote Desktop Server

In Use - Either your PC is already running a Remote Desktop Server, or the NAT/Firewall that you are behind has a Remote desktop server running already


Virtual Network Computing (VNC) Server Port 5900
When you want to remotely control a PC, VNC is a free network remote control utility that accepts incoming connections on port 5900.

Blocked - If this port is blocked, You will NOT be able to host VNC remote control sessions unless your VNC erver can be set to listen to another port. Typically VNC runs on port 5900-5904

Open - Ready to host your VNC remote control sessions.  Run the VNC Server and you and others instantly have access to remotely control your own server remotely!

In Use - Either your PC is already running a VNC Server, or the NAT/Firewall that you are behind has a VNC Server running already



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