Q: What does 'There is insufficient cached information to determine the next network at hop #' mean?

A: When DesktopPerspective successfully traces to a location, it saves that trace information -- so that if you trace to the same location, and you do not reach the destination, DesktopPerspective might be able to tell you what the next hop would have been -- allowing you to figure out that a router is down. So, this messages means that DesktopPerspective does not have a prior trace cached to tell you what the next hop should be.

 
Q: Will DesktopPerspective work through my company firewall / NAT server?

A: This depends upon how your firewall / NAT server is configured. Please ask your network administrator if your firewall (or NAT server) is configured to allow PING and TRACERT to work (which use ICMP ECHO, ECHO REPLY, and TTL EXPIRED packets). You can test this yourself by running these programs on your computer (For example, try "tracert www.visualware.com"). If these programs work, DesktopPerspective should work just fine on your computer. otherwise, your firewall (or NAT server) will have to be reconfigured by your network administrator to allow PING and TRACERT to work before you can use DesktopPerspective.

Once you can successfully run a traceroute, if you are not seeing the Whois contact information when clicking on an entry in the 'Node Name' or 'Network' column of the DesktopPerspective report table, your firewall administrator may also need to open port 43 to enable access to WHOIS information. Additionally, DesktopPerspective Server may be installed outside a firewall, and users inside the firewall may access it through a Java-enabled web browser such as IE or Netscape. This option provides users inside a firewall access to traceroute and ping information that other is blocked by the firewall.

 
Q: What does 'Connections to HTTP port 80 are being rejected' mean?

A: When you trace to a web site, such at www.yoursite.com, DesktopPerspective attempts to connect to the web site using the HTTP web protocol (which uses port 80). This means that the web site is not accepting connections. This also means that if you go into your web browser and go to address "http://www.yoursite.com" that it will not work.

 
Q: What do the colored lines on the map mean?

A: Links drawn in blue indicate known locations. Links drawn in purple indicate that a 'guess' was made. Guess locations are derived from domain registration (WHOIS) information.

 
Q: Can DesktopPerspective be run from a non 'Administrator' account on Windows NT/2000 Server?

A: Yes, just make sure that the user account has privileges to access the java folder in the Windows directory.

 
Q: Why is DesktopPerspective sending packets to UDP port 40000 on one of your servers?

A: DesktopPerspective has an option to report unknown node names to our server at 161.58.180.113. When a traceroute is run and DesktopPerspective sees a node name for the first time, it is reported back to us. This information is used to update our geographical database, so that newer releases of DesktopPerspective will have an updated and accurate geographical database.

If you prefer to turn off this reporting, you may do so within DesktopPerspective, in the Preferences dialog (Options, Preferences). Under the "Miscellaneous" section, you may turn off the reporting feature by deselecting the Report unknown node names to DesktopPerspective.com box.

 
Q: What does the 'TTL Bug' mean?

A: TTL stands for Time To Live. All IP packets have a TTL field and as IP packets get passed around the Internet, this TTL value is decreased, usually by one at every hop. If this field ever gets down to zero, the IP packet is discarded and does not reach its destination. What this means to you is that if you ever try to connect to a site on the Internet that is at a hop level greater than your TTL, your connection will fail.

The ICMP TTL Bug occurs in a TCP/IP stack when the incoming TTL value of a packet is not reset and sent out as the outgoing value (it should be initialized to some default value).

 
Q: What is a private use network, and why can't it be traced?

A: Private Use networks incorporate IP addresses that are reserved for internal use. When a traceroute is run, the IP address will go through a IP management utility which will change the IP address to enable it to be used externally. In DesktopPerspective, for any hops on a private use network the geographical location will not be shown, as these use pseudo IP addresses. All the other hops should work, if there are no firewalls or proxy servers in place.

 
Q: How do I install Java support?

A: Visit the Java Support web page for complete details. You will need to install a Java VM that is appropriate for your platform.

 
Q: Will DesktopPerspective work with a proxy server?

A: Most of DesktopPerspective will work just fine with your proxy server because most of the protocols that DesktopPerspective uses (like ICMP) are protocols that a proxy intercepts. However, testing connectivity to web servers may fail. Please note that if you are not even seeing traces in DesktopPerspective (which should work), that your personal or company firewall is probably blocking access. Refer to the firewall Q/A for details.

 
Q:  What if I need support?

A: Simply submit a Support Request  and we would be more than pleased to help you implement DesktopPerspective or answer any questions you may have.