Mac address / IPv6 does not match mac address for IPv4


I’ve been running my pihole for a few months with IPv4 now with no issues. I put myself on the dev branch yesterday. I was trying to add IPv6 internally by configuring my Ubuititi USG 3P to use IPv6 on the internal network. Settings for each side listed below:

USG settings:
IPv6 Interface type: Prefix Delegation
IPv6 Prefix delegation interface: WAN
IPv6 Prefix ID: blank
IPv6 RA: Enable IPv6 Router Advertisement
IPv6 RA Priority: High
IPv6 RA default lifetime: 86400 (default)
IPv6 RA Preferred lifetime: 14400 (default)
DHCPv6/RDNSS DNS Control: Auto

DHCPv6/RDNSS Name Server : fe80::60d3:xxxxxx:3ec (pulled the IPv6 address of my pihole from bash)

PiHole config:
PiHole Version: vDev (development, v4.0-142-g2cdbb34)
Web Interface Version** vDev (devel, v4.0-83-ga072c532)
FTL Version** vDev (development, vDev-7b01d20)
Enable IPv6 Support (SLAAC+ RA): Enabled.

The problems that I’m facing are

  1. The IPv4 and IPv6 addresses show up on two different lines.
  2. The Mac addresses show up differently for IPv4 and IPv6 for the same host. This probably is causing #1.
  3. resolving internal names e.g. unifi.lan does not work. This hostname has a static address in my pihole.
  4. my pihole doesn’t show my it’s IPv6 address just like Annotation%202018-11-06%20125007

(Dashboard Not Detecting IPv6 Address)

Any ideas why this would happen? Is this a configuration issue or a defect?


IPv6 does not use MAC addresses, it uses DHCP Unique ID’s (DUID). The concept is similar but the format of the address is different.


Please upload a debug log and post the token. Thanks.


Just pulled the Debug log. The token is 3erszc7zwx


From your debug log, it doesn’t appear that Pi-Hole is listening on the same IPv6 address:

*** [ DIAGNOSING ]: Networking
[✓] IPv4 address(es) bound to the eth0 interface: matches the IP found in /etc/pihole/setupVars.conf

[✓] IPv6 address(es) bound to the eth0 interface:
   2600:1700:8450:2aa8:f337:7331:76bf:d0ae does not match the IP found in /etc/pihole/setupVars.conf (
   fe80::60d3:a0e3:e707:d3ec does not match the IP found in /etc/pihole/setupVars.conf (

*** [ DIAGNOSING ]: Setup variables


cool thanks! that addressed that part of the issue that I was dealing with.


That fix also appears to have fixed this issue too:
resolving internal names e.g. unifi.lan does not work.


Got it. Didn’t know that. But the pihole duplicates each host. One entry is for IPv4 with MAC and the other has DUID (in the MAC address column) and IPv6 address. Maybe a way to handle that is create a separate column if it is issuing IPv6 addresses for IPv6 and DUID. I’m not sure how that will work for some IOT devices that you can’t change the hostname on though.