Troubleshooting Windows TCP/IP connections can be tricky because there are so many elements involved. Here is a brief guide intended to help users make sure they've checked all the essential components. Listed below are the most common causes of TCP/IP connection failures.
Note: Specific terminology is used throughout these instructions. It's important that this terminology is understood before reading the instructions:Guest: Computer initiating the Timbuktu Pro session.
Host: Computer on the receiving end of the Timbuktu Pro session.
- Make sure you have your Trusted Visitors setup correctly
Have you setup Timbuktu Pro to allow inbound users? If not, you may not be able to connect. Open up Timbuktu Pro on the Host system and go to Setup\Security and click on the Registered Users tab. Hit the Add Registered Users button to setup a username and password to remotely login to this system. Make sure to check off the services that you wish to allow this account to use and click OK. Please keep in mind the username and password are case sensitive. - Ping response time and packet loss
What is a ping? A ping is a method to determine whether a specific IP address is accessible. It functions by sending a packet to the specified address, waits for a reply and records the time the roundtrip takes. Typically Timbuktu Pro works best when the response time is under 200ms. Anytime the ping response time is higher than 200ms, Timbuktu Pro can time out or "give up" looking for the Host computer. If Timbuktu Pro does manage to make a connection, some of the packets may get lost. This can happen because Timbuktu Pro gives up sending some of the packets to the Host since the response time was so long. To determine if you have a high ping response time, go to the Start\Run menu on the Guest system, and type in Command. This will bring up the command prompt. Type in ping, followed by a space, and then the IP address of the Host system and press Enter. The results of the ping will be displayed on your screen. If the average response time is 200ms or higher, the response time is high and you may have trouble making a connection with Timbuktu (or any other application).If you do have a high response time, this is can be caused by several factors. The most common cause is network traffic. This may be traffic on your own private network or it could be on your Internet Service Provider's network. Trying a different Dial-Up number or disconnecting your broadband modem and reconnecting could help the situation. Connecting to a Host that's behind a router, can also cause slow the response times, since routers with older firmware often cause some packet loss. Try updating your firmware and then see if you can successfully connect .
If you are not able to ping the Guest, chances are there may be a firewall preventing a connection. If you are trying to connect through a firewall, the ports that Timbuktu Pro uses must be opened. The inability to ping can also be the result of using an outdated IP address or an internal IP address instead of a WAN IP address. To verify if you are using the correct IP address, open up a browser on the Host computer and go to the website www.whatismyipaddress.com or www.whatismyip.com .
- Personal firewalls
Do you have a personal firewall (i.e. Norton) that is blocking inbound access to your system? If so, the ports that Timbuktu Pro uses must be open. The ports UDP 407 and TCP 1417-1420 need to be opened on your firewall. Also, some personal firewalls may restrict connections to only allow connections from specified IP addresses. If this is the case, you'll only be able to connect to that system from an IP address that's specified in the firewall configuration, unless you update the configuration to allow connections from additional IPs. - Router not configured properly or not configured at all
If you have a router present there is a good chance you will need to make configuration changes to it in order to allow Timbuktu Pro to connect through, and to the proper machine on its Local Area Network (LAN). Your router may be assigning private IP addresses to your machines. These private IP addresses can only be accessed by other computers on the same LAN. In order for computers from outside of your routers network to make it into the proper machine, you will need to setup what is called port forwarding or port mapping on your router. To find specifics on where it may be located on your router, please check our router configuration guides for your routers make.http://www.netopia.com/support/howtodocs/router.html
For routers not listed or for troubleshooting your router, please contact your router manufacturer directly. We do have generic router guides available for both the Mac and Windows operating systems. These guides will give you the necessary information that you will need before you contact your routers support department for specific instructions.
Windows:
http://www.netopia.com/support/software/how2docs/win/nat.htmlMac:
http://www.netopia.com/support/howtodocs/mac/nat.html - Using an internal IP address instead of a WAN IP address
Verify the IP address that you are using to connect to the Host computer. If the IP address you are trying to connect to is a 192.168.xxx.xxx or a 10.xxx.xxx.xxx IP address, then this is the problem. These IP addresses are private IP addresses that are only accessible from other computers on the same Local Area Network (LAN). If the Guest computer is not on the Host's LAN, then a private IP address cannot be used to connect to the Host. In order to connect to a Host that's using a private IP address, you first need to configure your router to allow inbound Timbuktu Pro traffic. For instructions on configuring your router, please visit the following URL:http://www.netopia.com/support/software/how2docs/win/nat.html
- ISP blocking ports
Some ISP's block certain ports in order to keep users from creating their own virtual networks on their network or for security risks. We suggest that you contact your ISP directly to see if the Timbuktu Pro ports are opened on their network:Mac <-> Mac connections use TCP 407
Mac <-> PC connections use UDP 407 and TCP 1417-1420
PC <-> PC connections use UDP 407 and TCP 1417-1420 - Proxy Server
Unfortunately at this time Timbuktu Pro Windows does not support connections through proxy servers. - TCP/IP is not setup correctly
First make sure you can connect to the Internet via a web browser (i.e. Internet Explorer or Netscape Navigator). If you can, the next thing to look at is your TCP/IP settings. You can find these in your operating system's Network control panel. If you are connecting over a LAN, make sure that the subnet mask listed is the same on all machines involved in the connection. Also make sure that the IP addresses contain the exact first 3 sets of numbers (i.e. 192.168.100.3 and 192.168.100.4). If your systems are connected through a router, make sure the exact same router IP address is listed on all machines. If you have a broadband Internet connection and none of these suggestions change the outcome of your connection, contact your Internet Service Provider to verify that your TCP/IP settings are setup according to their specifications. - Hardware problems such as cables and ports on hubs/routers
Typically if you have a hardware issue with the cables or ports on the hub/router you may experience other TCP/IP problems such as not being able to see the Internet, not able to get e-mail, or not able to do file sharing with other machines on your local network. If you have any of these problems, you more than likely will have problems with Timbuktu Pro also.A simple way to test if the cable is the cause of any of these problems is to switch the Ethernet cable with an Ethernet cable from another machine that is working properly. If that does not resolve the issue, try moving the Ethernet cable from the problem system to another port on the hub, switch or router.
- VPN connection not allowing traffic through our ports
Please check with your Network Administrator to make sure the required Timbuktu Pro ports, UDP 407 and TCP 1417-1420, are open in the VPN to allow Timbuktu traffic through. One way to confirm this is to use a port-scanning utility (i.e. LanGuard, Sygate, PC Flank). You may also want to check with the router/VPN client's manufacturer to confirm that your configuration is correct. Please keep in mind that once your VPN is configured correctly, Timbuktu Pro should display an IP address that is associated with the remote network. You should be able to ping and trace route to other machines on the remote network as well. Timbuktu Pro's Chat, Notify, and Intercom services all use dynamic ports. These ports used by these services vary and are in the range 1023 and above. Netopia recommends that you open up a range of ports (i.e. 1023-1053) in order to allow these services to function properly.Note: Please keep in mind that in order for NT Authentication to work, the following ports must be opened as well.
TCP 139, UDP 138, UDP 137
- Cannot find Host using the Internet Locator (e-mail address)
If your connection is failing using Timbuktu Pro's IP Locator feature, there are several reasons why this connection can fail. For troubleshooting tips, please visit the following how-to-guide at: - Connecting to Hosts with dual Network Interface Card (NIC)
When attempting to connect to a system with dual Network Interface Cards (NIC's), Timbuktu Pro often displays the IP address from the incorrect NIC, which makes it impossible for another system to connect to it. For workarounds to this problem, please visit the following URL:http://www.netopia.com/support/software/how2docs/win/multihomed.html
- Win XP firewall enabled
Windows XP has a built-in firewall that blocks inbound access if enabled. To see if this may be the issue, go to: Network Places Properties> LAN Properties> Advanced> Internet Firewall on the Host system. - Windows 2000 TCP/IP Filtering enabled
Windows 2000 has a setting for TCP/IP filtering located in Network Places Properties> LAN Properties> Internet Protocol TCP/IP Properties> Advanced> Options. If this setting is enabled and Timbuktu Pro's ports are not specified, the connection will fail. You will need to either disable this feature or add Timbuktu Pro's ports