Cannot see other computers on network
If you cannot find networked computers or to tell if your ports are accessible:
1) Ping the machine by name or IP:
- Windows: Start > Run > Type: cmd.exe
- ping 192.168.0.1
2) Use Telnet to probe the machine by IP and port:
How To Use Telnet
Once you have the IP address, open a command prompt on the source computer:
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Windows: Start > Run > Type: cmd.exe
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Mac: Utilities > Terminal
Enter command:
telnet IP_ADDRESS_OF_DESTINATION_COMPUTER 4242 (e.g. telnet 54.162.1.10 4242)
If telnet can successfully connect, you will see an encrypted connection string (a bunch of unintelligible text). Example:
imac2:~ Renee$ telnet 54.162.1.10 4242 Trying 54.162.1.10… Connected to 54.162.1.10. Escape character is '^]'. ??d???t”??Y+???+|???Ø?d6#?еW?{?????6ß?D!@g?????l?????>?]??b6`Û??gÖ²$d?cÎ?
If telnet cannot successfully connect, you may see connection refused, no response or some other response. Proceed to step 3.
Tips for Using Telnet to Isolate the Issue
Focus on getting telnet to connect successfully in one direction to help isolate the issue. Test to see if you can connect from Computer A (source) to Computer B (destination).
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Check the software firewall on Computer A and run the telnet test from Computer B to Computer A.
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Try disabling your software firewall and 3rd party security software and test again.
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If the test passes, then you know you have a configuration issue with your software firewall or security software. Consult your manufacturer documentation on how to configure an exception for CrashPlan on TCP port 4242.
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With your software firewall or security software still disabled, check the router configuration at Site A. Consult your router manufacturer’s documentation to make sure your router is configured properly to allow the incoming connection from Computer B. Test again after making any modifications to the router configuration.
Installing Telnet on Vista
Telnet is not installed by default in Vista. To install Telnet, please follow these instructions:
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Click Start then select Control Panel.
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Select Programs and Features.
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Select Turn Windows features on or off.
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Select the Telnet Client option.
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Click OK.
A dialog box will appear to confirm installation. The telnet command should now be available.
3) Use Netstat to find all ports already being used and whether your ports are open:
Windows:
netstat -ano
Mac / Linux:
netstat -an
Choose another port if something is already listed under the number you’ve selected.
Once you find an unused port, you can change the listening port option in CrashPlan: Settings > Backup > Inbound Backup Settings. Make sure to set up port forwarding for that port, as well.
If you need to open a port:
Configure Port Forwarding
If the telnet connection fails, enable port forwarding on your router for incoming connections on the port you need. There is some great information about port forwarding including tutorials for various router makes and models at www.portforward.com.
