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ish-app / ish

Linux shell for iOS
https://ish.app
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How "/etc/resolv.conf" is configured? #1896

Open nexttoyou opened 2 years ago

nexttoyou commented 2 years ago

Dear experts,

it is quite annoying that my /etc/resolv.conf (iPad with ish downloaded from the official app store) looks like this:

search local
nameserver 198.18.0.1

Addresses from the range 198.* are used nowhere in my local network. The DNS is done by an OPNsense device being served by two different Pi-hole servers (more or less as described here). It is a dual stack IPv4/IPv6 environment and I'd very much like to be able to define the correct DNS server somewhere in the ish preferences as "198.18.0.1" doesn't even know my local network devices for whatever reason. Changing /etc/resolv.conf doesn't work as it is overwritten when restarting ish.

I'm currently confined to bed so any solution (couldn't live without ish as it gives freedom) would be profoundly appreciated!

Further questions are happily answered!

tbodt commented 2 years ago

/etc/resolv.conf is configured from your system dns settings using libresolv. What does the settings app show as dns settings? Open wifi settings, tap the (i) next to your network, tap Configure DNS, and send a screenshot of that page.

nexttoyou commented 2 years ago

Additional investigation gave me the following result: if you have installed AdGuard (Pro) on your iDevice with DNS protection enabled, then this DNS server will be used under the address "198.18.0.1" (coming from the installed AdGuard profile) for ish. While this (again) means that it is indirectly (via "198.18.0.1") my proper DNS server under its external IPv4 address it naturally cannot and should not resolve local IP addresses. So if anybody here is able to tell me how to automagically change the DNS with every ish restart (/etc/profile perhaps?) I'd love to hear it!

nexttoyou commented 2 years ago

/etc/resolv.conf is configured from your system dns settings using libresolv. What does the settings app show as dns settings? Open wifi settings, tap the (i) next to your network, tap Configure DNS, and send a screenshot of that page.

The settings show what they should show but not "198.18.0.1". Unfortunately, in my case ish and AdGuard are a bad combination. Would an automatic DNS change at ish startup be imaginable? Would be most probably too easy …

nexttoyou commented 2 years ago

Like imagined before I was successful using /etc/profile in my favour. If you'd like to see what I've done I'd be happy to show my dirty little DNS hack at this place (but do not hate me for any complications that might follow).