Online Help

Failed to connect to server

This is a general error that indicate the server could not be reached.

Possible causes
A) DNS name unknown
C:\>ping myserver
Ping request could not find host myserver. Please check the name and try again.
CHECK DNS

B) The ip address is unreachble, no gateway defined
C:\>ping 167.27.36.65
Pinging 167.27.36.65 with 32 bytes of data:
Reply from 194.7.90.33: Destination host unreachable.
Reply from 194.7.90.33: Destination host unreachable.
Reply from 194.7.90.33: Destination host unreachable.
Reply from 194.7.90.33: Destination host unreachable.
Ping statistics for 167.27.36.65:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms
CHECK GATEWAY

C) The ip is reachable, gateway ok, but server don't answer.
Is the server PC runnning?
C:\>ping 172.20.222.20
Pinging 172.20.222.20 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Ping statistics for 172.20.222.20:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),
CHECK SERVER PC's NETWORK

D) The server is online and can be reached
C:\>ping 172.20.222.166
Pinging 172.20.222.166 with 32 bytes of data:
Reply from 172.20.222.166: bytes=32 time=1ms TTL=255
Reply from 172.20.222.166: bytes=32 time<1ms TTL=255
Reply from 172.20.222.166: bytes=32 time<1ms TTL=255
Reply from 172.20.222.166: bytes=32 time<1ms TTL=255
Ping statistics for 172.20.222.166:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 1ms, Average = 0ms
SERVER PC NETWORK IS OK

    a) Is Vnc running on that PC ?
    b) Is the server and viewer port the same ?
    c) Verify if the port can be reached via telnet
    Sample:
        Server runnning on 172.20.214.2 port 5900
        Wrong port answer
            C:\>telnet 172.20.214.2 5901
            Connecting To 172.20.214.2...Could not open connection to the host, on port 5901
            : Connect failed
        correct port answer
            C:\>telnet 172.20.214.2 5900
            RFB 003.006


            Connection to host lost. (timeout because telnet didn't answer correct, normal)



If telnet works, but viewer fails. It could be
that your firewall ( like the buildin MS firewall) block outgoing traffic based on application.
Telnet is allow, vncviewer is blocked.
Try to temporal disable the firewall to check this it.

For Windows XP/2003 or better:
Goto Control Panel, Windows Firewall and turn it off.
Try again to connect.
If it works, turn the firewall back on, goto the Exceptions tag and "Add Program" (UltraVNC).
This needs to be done on both machines.
If this still doesn't work go back to the Windows Firewall and "Add Port" 5900.

For Windows 2000 or before:
Consult the manual for your firewall and make sure that the port 5900 is unblocked.

Another solution is to make sure that your cable or dsl modems do not have a firewall active in them. Speedstreams has a few models like 5200, 5400 that some ISP have on by default.