Trying To Access My Calibre Library on my iPad via a server

[Sahara888]

I originally posted this in the devices thread on the main forum page by mistake...

Hi there, I don't know if you can help, but I'm trying to access my Calibre library via the server on my iPad. Although I have created a forwarded port for calibre (port #1024) I can't seem to get access to it from within the wifi/network. It used to work on my data, but not anymore. If anyone can offer any advice I'd really appreciate it.

[AnemicOak]

Link to other thread with more info...
https://www.mobileread.com/forums/sho...d.php?t=270747

[MizSuz]

Sahara moved it over here because she didn't realize there was a calibre specific forum. But yeah, there is additional info on the other board. Thanks for the link to it, AnemicOak!

[eschwartz]

For future reference, see the Posting Guidelines, point #3:

Do not post the same discussion in more than one forum. Try to pick the most relevant forum for your post.

[...] you think you may have chosen the wrong forum, report your post and ask the moderators to move it to the right forum.

It helps to keep information together.

[eschwartz]

From the other thread:

Originally Posted by MizSuz

Hi folks, I've been working with Sahara on this one and it's been quite a challenge.

Initially we set her calibre server up and she was only able to access it using data, no wifi connection (either from work or from her workplace) would enable her to access it but she could access it through her data plan and I could access it from an adjacent country. Since then it's quit working all together and neither of us can access it regardless of how we try.

She's hosting the calibre server on her iMac (and my Apple knowledge is dismal) and is using a Sagemcom router. She uses an ipad and an android phone to try to access the server.

I set her calibre server up exactly like mine is set up on my Win7 machine, and I have no issues at all and am able to access my server using the external ip addy url with the proper port whether on a wifi connection or a data plan. I am starting to think this is caused by some nefarious Apple setting that I have yet to identify.

So when you say it cannot be accessed through WiFi, do you mean using the external world-accessible IP, or via the internal LAN IP?

There is no good reason for the internal IP to fail when used from a device connected to the same WiFi network.
The external IP over 3G data is dependent on whether or not you have correctly set up port forwarding in your router.


You might not be able to access the external IP from within the LAN, depending on whether your router knows how to do NAT loopback.

[chaley]

Originally Posted by eschwartz

There is no good reason for the internal IP to fail when used from a device connected to the same WiFi network.

Actually, there is, as we have discovered time and time again with CC. Some home routers come with one of "wireless guest mode" or "wireless isolation" enabled by default, or the user enabled one of them without knowing what it did. Either of these can prevent a device from seeing other devices on the home network. Another reason that connections might not work is caused by dual band wifi routers that don't by default route from one band to the other.

[Sahara888]

Yes, thank you very much AnemicOak for posting the link. I appreciate it.

[eschwartz]

Originally Posted by chaley

Actually, there is, as we have discovered time and time again with CC. Some home routers come with one of "wireless guest mode" or "wireless isolation" enabled by default, or the user enabled one of them without knowing what it did. Either of these can prevent a device from seeing other devices on the home network. Another reason that connections might not work is caused by dual band wifi routers that don't by default route from one band to the other.

Can I justify myself by arguing that that still isn't a "good" reason?

[MizSuz]

This is helpful and gives me a place to look and futz around. I set her up exactly like mine and I can access mine both with the internal url and the external url from my home wifi, and from the external when away from home whether from someone's wifi or my data plan.

Her router is different than mine is, though, and there may be something specific to her router that I am missing.

[MizSuz]

We got it working but it's the oddest thing. If she is on her wifi she can only access it by using the internal IP address, the external address just won't work. If she gets off her wifi and gets on her data plan then she, obviously, can only access it with her external IP address.

She just can't access it using the external IP address if she is on her wifi. I've never seen anything like that before. On my own system I can use the external IP address from any browser regardless of connection.

I have some sense that it's probably some ridiculous Apple setting, but I tend to blame Apple for anything stupid by default, particularly if it's not user friendly and seems to want to keep you in the walled garden.

[chaley]

Originally Posted by MizSuz

She just can't access it using the external IP address if she is on her wifi. I've never seen anything like that before. On my own system I can use the external IP address from any browser regardless of connection.

This is rather common. Many routers (to go out on a limb, I think it is most routers) do not support the "loop back" required to make internal-to-internal connections via an external address. A few routers require some kind of set up to make it work.

The reason that router support is necessary is that it is the only piece of equipment that can know that it is both the source and the destination of a packet. In addition, it needs the smarts to do any port mapping when it sends the packets back onto the local LAN.

[theducks]

Originally Posted by MizSuz

We got it working but it's the oddest thing. If she is on her wifi she can only access it by using the internal IP address, the external address just won't work. If she gets off her wifi and gets on her data plan then she, obviously, can only access it with her external IP address.

She just can't access it using the external IP address if she is on her wifi. I've never seen anything like that before. On my own system I can use the external IP address from any browser regardless of connection.

I have some sense that it's probably some ridiculous Apple setting, but I tend to blame Apple for anything stupid by default, particularly if it's not user friendly and seems to want to keep you in the walled garden.

I agree with Chaley. Looping back on ones IP is not usually supported.

Testing WITH the dataplan is one good way if you don't have a neighbor/buddy with their own broadband

on needing to configure the router,
Many folk have just one device that uses the broadband, the computer.
This is becoming less common with many having Smartphones and other Network (WiFi and Wired) devices. When a call comes in, you need to tell the router "who will handle the port 8080 calls". Each port can only have 1 target. Some routers allow you to also Map the port as well as the target IP . call for port 8083 gets mapped to computer3 port 8080 (the one you would use for internal use)

[eschwartz]

Originally Posted by MizSuz

We got it working but it's the oddest thing. If she is on her wifi she can only access it by using the internal IP address, the external address just won't work. If she gets off her wifi and gets on her data plan then she, obviously, can only access it with her external IP address.

She just can't access it using the external IP address if she is on her wifi. I've never seen anything like that before. On my own system I can use the external IP address from any browser regardless of connection.

I have some sense that it's probably some ridiculous Apple setting, but I tend to blame Apple for anything stupid by default, particularly if it's not user friendly and seems to want to keep you in the walled garden.

Well, I hate to take away your excuse for blaming Apple () for something, but I did say:

Originally Posted by eschwartz

You might not be able to access the external IP from within the LAN, depending on whether your router knows how to do NAT loopback.

Now, as it happens my router does support NAT Loopback. Lucky me. But as chaley said, many (most) do not.
It isn't a matter of maliciousness either -- it just requires sufficient "intelligence".
You can edit /etc/hosts on the computer to reroute the Dynamic DNS url (I assume you have one?) or use a private DNS server to catch all traffic on the LAN and redirect it to the internal IP. But this might be more work than you want...


Oh, by the way -- what turned out to be the problem?

[theducks]

and many WiFi routers default to preventing Peer (WiFi to WiFi) connections as part of a GOOD security model (Stops...OK Slows down, the bad guys with a laptop just outside your walls from getting in)

[MizSuz]

Originally Posted by eschwartz

Oh, by the way -- what turned out to be the problem?

The problem turned out to be that she needs two addresses and the knowledge to know which one to use depending on which connection she is using.

In fairness this blind sided me and since I was totally confused by it I couldn't advise her properly. Apparently my modem does have this loop-back functionality of which you folks speak so I was oblivious to modems not having it. I set hers up pretty much the way I set mine up but she didn't get the same results.

It's working now and she understands when to use which url so I guess it's all good. Coming here helped give me the confidence to believe that I wasn't doing it wrong to begin with.

Well, I hate to take away your excuse for blaming Apple () for something,

It's ok, I've been hurling epithets at Apple since 1993, I'm sure I'll find something else to whinge about when it comes to dealing with them.