Need help with part-time internet and DNS

[MacinJosh]

I have a problem. I live in Papua New Guinea as a missionary and am setting up a LAN for the bible college and using SLS as a server. I've set up everything internally just fine. Problem arises when I connect to the internet on the server (which is my sole computer). Let me break down the situation.

• PNG does not have unlimited broadband and my location only has dialup and GPRS with very restricted monthly quotas. Always on solution is a nono.
  
• I connect to the internet using my iPhone tethering by USB.
  
• I don't have a real domain and I use an internal DNS server setup for the domain ibc.network
  
• Server IP is 192.168.1.1 and DNS is set properly and works.

Problem: when I connect the iPhone the internet won't work unless I set the service order for the iPhone to be above Ethernet. Once I do that the internal network fails to resolve ibc.network to 192.168.1.1. Any internal wiki gets the OpenDNS error page. I have no idea how to fix this as I'm fairly newby and my limited monthly quota restricts me from doing heavy googling to find out. I did try to find help but couldn't find any relevant article.

I have no intention of sharing my internet connection. It's just for me.

I'd really appreciate any help.

Joshua.

 

[belvdr]

Can you configure the SLS DNS service to forward external requests to OpenDNS (208.67.222.222 and 208.67.220.220)? If you can't use those servers, use the the DNS servers assigned by your tethered device.

Also, ensure you do _not_ have a default gateway set on your Ethernet interface.

 

[timbloom]

Is this only happening to the server, or other machines on the network?

I suspect the problem lies in the DNS settings of your tethered connection. Make sure to add your local server there manually, otherwise it probably won't even attempt to use the internal network for any dns lookups, asking only opendns "who is server.local?", and since opendns responds with a valid response, it never looks anywhere else. Even though opendns will direct you to an error page, the dns response itself says it found the site.

There really could be a lot of different reasons this is happening, depending on setup. Is the computer acting as a gateway for other machines while tethering is on, or are you just using it for internet access from that server only?

 

[MacinJosh]

Is this only happening to the server, or other machines on the network?

I suspect the problem lies in the DNS settings of your tethered connection. Make sure to add your local server there manually, otherwise it probably won't even attempt to use the internal network for any dns lookups, asking only opendns "who is server.local?", and since opendns responds with a valid response, it never looks anywhere else. Even though opendns will direct you to an error page, the dns response itself says it found the site.

There really could be a lot of different reasons this is happening, depending on setup. Is the computer acting as a gateway for other machines while tethering is on, or are you just using it for internet access from that server only?

Good call. While the iPhone USB interface doesn't allow to change DNS settings, the Bluetooth PAN interface does. While tethering by BT with local DNS settings applied, it works the way it should. Thanks!

This affected all computers on the network. As soon as I tethered the iPhone the local wiki pages gave OpenDNS error pages. The computers don't have a router specified on the IP settings and ibc.network resolved to an outside IP when the tethering was on. It's not a registered domain, just a private internal one.

Is there another solution on the server side to completely not allow any ibc.network requests to go outside?