New Problems With Local Dns Resolution Because Net.ppp0.dns1 Is Set To 8.8.8.8


Robin Smidsrød

Members
Oct 10, 2016
1
13
I've noticed that these lines are added at the end of /system/build.prop:

net.ppp0.dns1=8.8.8.8
net.ppp0.dns2=8.8.4.4
net.dns1=8.8.8.8
net.dns2=8.8.4.4

The entries in net.dns1 and net.dns2 are properly replaced with DHCP-provided information, but net.ppp0.dns1 and net.ppp0.dns2 are not unset when DHCP-provided information is available, which are causing multiple DNS lookup-related issues. By running wireshark/tcpdump on my edge router, I've noticed that 8.8.8.8 is contacted directly instead of my local DNS resolver (provided by DHCP). For some reason there are just some applications that use the info from net.ppp0.dns*, or it happens only in certain situations (which I haven't been able to debug which are yet).

Right now I've set up some iptables rules on my firewall to forcefully redirect these DNS packets to the local DNS resolver instead. That's a poor band-aid solution to the problem.

Is it possible to have these entries removed from /system/build.prop? If not all of them, then maybe just net.ppp0.dns1 and net.ppp0.dns2, as they are not "disabled" properly when DHCP provides proper information?

I'm using a Xiaomi Mi 5, running EU weekly ROM version MIUI 8.1 by xiaomi.eu 6.9.22 Beta.

-- Robin