Calibre Companion not connecting

[kwemheuer]

Hi,

I am testing the demo version prior to buy the fully featured version.
But the companion is not connecting.

The server is running (192.168.10.7:8080). I can access the server via
browser. The client is on my wlan, which uses a routed network
192.168.26.0/24 (Client on 192.168.26.98). I check the network with
"wireshark" and I can see, that the client sets up a connection and
terminates the connection without any data transfer.

Any help would be appreciated.

Thanks in advance

Karsten Wemheuer

[chaley]

Originally Posted by kwemheuer

Hi,

I am testing the demo version prior to buy the fully featured version.
But the companion is not connecting.

The server is running (192.168.10.7:8080). I can access the server via
browser. The client is on my wlan, which uses a routed network
192.168.26.0/24 (Client on 192.168.26.98). I check the network with
"wireshark" and I can see, that the client sets up a connection and
terminates the connection without any data transfer.

Any help would be appreciated.

Thanks in advance

Karsten Wemheuer

Have you gone through our FAQ on connecting to calibre?

What you describe sounds like the antivirus or the firewall on the calibre computer is blocking CC's connection. The reason that CC would terminate the connection is that calibre does not send any data, or that the connection was never actually made. Also, if there is a router between the device running CC and the calibre server then you must enter the calibre IP address and port into CC. The auto connection won't work.

When you say that you can access the server using a browser, on what computer are you running that browser? My guess is that it isn't the device running CC.

[kwemheuer]

Hi,

yes, I go through the FAQ. There is no firewall.

I have a wireshark network trace showing the successfull tcp connect but no data transfer. With an active firewall there would be no connect.
There is no firewall, just routing between the WLAN network 192.168.26.0/24 and the LAN 192.168.10.0/24. But there is no multicast between the networks. Therefore I configured fixed IP/Port in the CC.

The connect from the browser is done from the same device as the CC.

Any ideas?

Thanks in advance,

Karsten

[chaley]

Originally Posted by kwemheuer

Hi,

yes, I go through the FAQ. There is no firewall.

I have a wireshark network trace showing the successfull tcp connect but no data transfer. With an active firewall there would be no connect.

Not quite true. There could be a connect to *something*, just not calibre. This happens all the time when "network security suites" are installed.

There is no firewall, just routing between the WLAN network 192.168.26.0/24 and the LAN 192.168.10.0/24. But there is no multicast between the networks. Therefore I configured fixed IP/Port in the CC.

The connect from the browser is done from the same device as the CC.

Any ideas?

Seriously, you have no firewall installed on the calibre computer or on any router between the device and the calibre computer?

Are you using HTTPS with a self-signed cert? CC does not support these. All the site certs, intermediate and otherwise, must be installed on the device running CC.

Is CC using exactly the same URL as you are typing into the browser? In other words, does http://192.168.10.7:8080/opds/ work in the browser? If you are doing some sort of reverse proxy then this URL might fail.

Send yourself a CC debug log (CC / Settings / Other / Send a debug log). That will tell you if CC thinks it connects but fails to send data, or if CC thinks it does not connect.

Some linux users have reported that linux thinks that calibre is doing a SYN flood. Turning on SYN cookies fixes that.

Other than these I don't know what else to suggest.

[kwemheuer]

Hi,

finally I got it working. But I don't know why...

There is no firewall active. From the browser on the tablet I can call the url http://192.168.10.7:8080 (show GUI) and http://192.168.10.7:8080/odps (gets XML).

Under "settings" in CC there are "wireless" and "Content Server". First try was to put IP-address and port number under "wireless". Now I switched to "Content Server" and put the settings in this form.

Now it is working. I don't know the difference between the settings, but anyway....

Thanks for Your support!

Best regards,

Karsten

[chaley]

Ahhh, I briefly wondered whether you were setting up the wireless device but using the content server. Glad you got it working.

The Content Server and Wireless Device connections are fundamentally different. The Wireless Device connection is used to connect to calibre as an e-reader "device" such as a kindle, a kobo, or an MTP device. Calibre can update metadata on a device, sending changes to books. The Content Server connects to calibre as a web (OPDS) client. This connection cannot automatically update metadata.

This FAQ might help explain the differences: What are the differences between Content Server, Cloud, and Wireless Device connections?

[kwemheuer]

Hi,

thanks for the details. It would be nice to get the wireless device connection working. What are the networking differences between the connection types?

For the moment I will live with the content server connection.

Thanks

Karsten

[chaley]

Originally Posted by kwemheuer

Hi,

thanks for the details. It would be nice to get the wireless device connection working. What are the networking differences between the connection types?

Up through the TCP layer there isn't any significant difference. Both make TCP connections to a listening calibre server. However, at the application level the two are completely different.

The content server is a "pure" HTTP connection, where the client has control. You (the user) talk to CC, not calibre. The client asks the server to do things for it. The server is stateless. The server can support multiple clients connecting at the same time.

The wireless device is a private application protocol based on JSON. After connecting, the client (the device) is passive, waiting for calibre to tell it what to do. You (the user) talk to calibre, not CC. Neither the client nor the server are stateless. Calibre can support one device connection at a time (any device, not just a wireless device). Calibre keeps information from connect to connect (a cache file) that reduces the time required to send metadata updates to the client.

In both cases you must tell calibre to start the appropriate server, providing the port that the server is to use. You do this using calibre's Connect/Share toolbar button.

It is rare that CC can connect to a calibre instance with one connection type but not with the other. Failures are almost always related to firewall rules and anti-virus software.