[chaley]

Originally Posted by LadyKoori

In the meantime, I'm using Win7 as an OS.

To check if one device/computer can "see" another device at the basic network level, do something like the following. In this example, you would using your windows machine and checking if it can see your phone/tablet.

1. Start CC. Go to settings, IP address and port. Note the IP address displayed in the dialog.
2. Open a command prompt. There are various ways to do this. On Win7 you should have a "Command prompt" shortcut in the start menu Accessories group.
3. In the command prompt, type "ipconfig" (no quotes). You will see output like the following. Look for the line that says IPv4 address. It should be very similar to the address you noted in CC. Probably both start with 192.168.N, where the N is the same on both machines.
   

   Windows IP Configuration
   
   
   Ethernet adapter Local Area Connection 2:
   
      Media State . . . . . . . . . . . : Media disconnected
      Connection-specific DNS Suffix  . :
   
   Ethernet adapter Local Area Connection:
   
      Connection-specific DNS Suffix  . :
      Link-local IPv6 Address . . . . . : fe80::8452:7346:aade:fbda%10
      IPv4 Address. . . . . . . . . . . : 192.168.120.38
      Subnet Mask . . . . . . . . . . . : 255.255.255.0
      Default Gateway . . . . . . . . . : 192.168.120.1
   
   Tunnel adapter isatap.{850AA568-3020-4789-B1B0-2058B85B1B38}:
   
      Media State . . . . . . . . . . . : Media disconnected
      Connection-specific DNS Suffix  . :
   
   Tunnel adapter isatap.{079F0E0A-8581-485F-BE57-EE3E77DEA19E}:
   
      Media State . . . . . . . . . . . : Media disconnected
      Connection-specific DNS Suffix  . :

4. At the command prompt, type "ping IP-address-of-phone", no quotes, replacing IP... with the IP address you noted above. You should see something like:
   

   d:\CBH_Data\calibre.git>ping 192.168.120.6
   
   Pinging 192.168.120.6 with 32 bytes of data:
   Reply from 192.168.120.6: bytes=32 time=135ms TTL=64
   Reply from 192.168.120.6: bytes=32 time=46ms TTL=64
   Reply from 192.168.120.6: bytes=32 time=261ms TTL=64
   Reply from 192.168.120.6: bytes=32 time=184ms TTL=64
   
   Ping statistics for 192.168.120.6:
       Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
   Approximate round trip times in milli-seconds:
       Minimum = 46ms, Maximum = 261ms, Average = 156ms

   If you get the following then the PC running calibre has no connectivity with the phone, perhaps because of a firewall but in your case probably because of the router

   d:\CBH_Data\calibre.git>ping 192.168.120.5
   
   Pinging 192.168.120.5 with 32 bytes of data:
   Reply from 192.168.120.38: Destination host unreachable.
   Reply from 192.168.120.38: Destination host unreachable.
   Reply from 192.168.120.38: Destination host unreachable.
   Reply from 192.168.120.38: Destination host unreachable.
   
   Ping statistics for 192.168.120.5:
       Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

5. If you are willing, then it would be good to check the other direction: phone to PC. Install a free network app on your phone. I use Ping & DNS. If you run the app, choose "Ping", and enter the IP address of the PC, you should see something like the following:
   
   If you do not (you see "Destination Host Unreachable) then you almost certainly confirmed that the router is blocking connections between the device and the PC.