Content Server on Windows 10 (Surface Pro), Can't access IP:PORT in browser on macOS

[01100001]

Hello,

While I've known about Calibre for a while and been using it for conversions for a while now, I only just started customizing and using it for library/content management.

The documentation being excellent, I've been able to find answers to most of my queries, either there or a bit of googling (site:www.mobileread.com QUERY). This appears to be an exception where none of the solutions have worked for me.

The Setup & the Problem

Running Calibre 6.3 on Windows 10 Home on a Surface Pro 7 device.

Started Content Server from the main menu > Connect/share > Start Content server. The menu now shows Stop Content server [192.168.31.112, port 8080, HTTP]. Tested to be working in the browser using Visit Content server in browser (from the same menu) which takes me to http://127.0.0.1:8080 in my default browser (Google Chrome).

Then when I visit http://192.168.31.112:8080 in Google Chrome, I am greeted with this error.

This site can’t be reached

http://192.168.31.112:8080/ is unreachable.

ERR_ADDRESS_UNREACHABLE

What I've tried

• ✅ Confirmed 192.168.31.112 is the correct device IP, both on the device (using an ipconfig command) and on the router (admin interface).
  
• ❌ Turned off Windows Defender/Firewall completely, for both private and public networks. Restarted Computer and Calibre.
  
• ❌ Pinged 192.168.31.112. It times out. But does it matter?
  
• ❌ Tried fiddling with port forwarding rules on my router to no avail. But honestly, I am not even sure I'm doing it right, because I'm clueless about these things.
  
• ❌ Attempted setting up a home network so I could connect my Windows 10 (Surface Pro 7) and macOS (MacBook Pro running macOS Catalina 10.15.7) devices. Gave up because it seemed a bit too complex and I wasn't even sure it was going to help.

Question(s)

The manual page makes it seem like this shouldn't be complex at all. So, what am I missing?

Could someone help me out? Assume that I am a noob and please try to be as detailed as possible.

Thank you!

[DNSB]

Originally Posted by 01100001

[*] ❌ Pinged 192.168.31.112. It times out. But does it matter?

If you can't ping the address, it's unlikely that you will be able to connect to it over HTTP/HTTPS.

In Windows Defender Firewall with Advanced Security, did you try settings all the profiles so Inbound Connections that do not match a rule are allowed when testing? You may have Domain/Private/Public or Private/Public depending on the Windows variant.

What is the IP address on your MacOS machine? In the same subnet as your Windows machine? Port forwarding should not matter since to use a 192.168 private address (see RFC-1918 for the definition of private network blocks), you would need to be connected to the same router. If you are trying to connect from outside your local network, then you would need to start worrying about port forwarding and what external IP your router is using.

[theducks]

additionally: Some (most) WiFi routers block connections on the same LAN by default.
Also, both must use the same band. 2.4 or 5.0
Having the host on a wired network is a Plus

[chaley]

Originally Posted by theducks

additionally: Some (most) WiFi routers block connections on the same LAN by default.
Also, both must use the same band. 2.4 or 5.0
Having the host on a wired network is a Plus

Assuming wifi, in addition:

• Both machines must be on the same SSID.
• The SSID must not be a "guest network".
• To add to @theducks first line, the router must not have "Wireless Isolation" (or something similarly named) turned on.

[01100001]

Enabled echo/ping requests as advised by @DNSB, following both these tutorials: https://kb.iu.edu/d/aopy and https://www.howtogeek.com/howto/wind...ista-firewall/. For some reason this didn't allow pinging immediately, even after a restart. But it did work later magically, somehow! (Two things I did during this time: Changed WiFi security from WPA/WPA2 to WPA2 and then router got restarted.)

Also, during the time the above wasn't working, I looked into other suggestions.

Originally Posted by theducks

additionally: Some (most) WiFi routers block connections on the same LAN by default.
Also, both must use the same band. 2.4 or 5.0
Having the host on a wired network is a Plus

Checked router settings. Didn't find any isolation or LAN blocking settings.

Confirmed both computers are on same band (2.4 GHz).

Originally Posted by chaley

Assuming wifi, in addition:

• Both machines must be on the same SSID.
• The SSID must not be a "guest network".
• To add to @theducks first line, the router must not have "Wireless Isolation" (or something similarly named) turned on.

Both machines are on the same SSID i.e. showing same router name. I don't how it could be done any other way.

Nope, not signed into guest network.

No Wireless isolation or related settings found.

Anyway, the issue has been resolved by enabling pinging on the Windows 10 device hosting Calibre Content Server.

Thank you so very much!

[01100001]

Originally Posted by 01100001

Enabled echo/ping requests as advised by @DNSB, following both these tutorials: https://kb.iu.edu/d/aopy and https://www.howtogeek.com/howto/wind...ista-firewall/. For some reason this didn't allow pinging immediately, even after a restart. But it did work later magically, somehow! (Two things I did during this time: Changed WiFi security from WPA/WPA2 to WPA2 and then router got restarted.)

Three things, actually. I also did turn Windows Defender Firewall off/on during this time. It wasn't working immediately after that though. Only noting this just in case it's relevant.

[01100001]

Note to self: If you are unable to ping again for some reason (and therefore cannot access Calibre Content Server), see if restarting the router fixes it.

If that doesn't work, reset the Windows Defender Firewall rules (Control Panel > Windows Defender Firewall > Restore defaults, or Control Panel > Windows Defender Firewall > Advanced settings > Inbound Rules, and manually remove the rules), add the rules again, then restart the router.

Unsure why this might happen (happed only once to me), but if it was working before, one of these should do the trick.