[FS#597] Unchecking "Use DNS servers advertised by peer" has no effect for IPv6

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - Marcel Menzel (Typhoon31) 

Attached to Project - LEDE Project
Summary - Unchecking "Use DNS servers advertised by peer" has no effect for IPv6
Task Type - Bug Report
Category - Base system
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Very Low
Priority - Very Low
Reported Version - lede-17.01
Due in Version - Undecided
Due Date - Undecided
Details - Hi everyone,

When the option "Use DNS servers advertised by peer" has been unchecked, LEDE still writes the advertised peer DNS Servers for v6 into /tmp/resolv.conf.auto:

# Interface wan
# Interface wan_6
nameserver xxx 
nameserver xxx

The IPv4 nameservers just disappear in this file, and on the overview page, these two v6 DNS Servers still appear on the "network" section (without their v4 counterparts).

To actually force dnsmasq to ignore these two, I have to check "Ignore resolve file" in the dnsmasq configuration.

I'm running LuCI lede-17.01 branch (git-17.051.53299-a100738) / LEDE Reboot 17.01.0-rc2 r3131-42f3c1f on a Linksys 1900ACS v2.

My WAN connection is a PPPoE connection with "Use builtin IPv6-management" checked and the option below set to "automatic". 

 

One or more files have been attached.

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=597