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pszafer

Member

Registered: 2015-01-22

Posts: 38

Systemd-resolve and NetworkManager

Hello,

I want to try out systemd-resolve as my main dns client.
In my house everything works out pretty well, but in my parents house for some reason NetworkManager is sending to systemd-resolve such config (IPv6 included, but router has no IPv6 configured...):

Link 2 (wlp4s0)
      Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6
       LLMNR setting: yes
MulticastDNS setting: no
      DNSSEC setting: no
    DNSSEC supported: no
         DNS Servers: 192.168.1.1
                      fe80::6666:b3ff:fe16:4b12
          DNS Domain: mydomain.com
                      ~lan

Router is pfSense with IPv6 disabled for most functions.
Anyway I can't find where is this DNS v6 address taken from...

systemd-resolve google.com
google.com: resolve call failed: No appropriate name servers or networks for name found

Setting of NetworkManager.conf

[main]
dns=systemd-resolved

If I disable IPv6 in NetworkManager then dns is working.

Any hints where to look for misconfiguraton?

lo1

Member

Registered: 2017-09-25

Posts: 584

Re: Systemd-resolve and NetworkManager

You already got this: any ipv6 address starting with "fe80::" is called a link-local address, generated by a process called EUI-64, specific to any IPV6 capable network host: since DHCP is enabled for both IP versions, your router is handing out his ipv6 link-local address.

Your PC thinks of it as a valuable DNS server (it takes higher preference over any ipv4 DNS server) and sends requests to translate hostnames into IPV6 addresses.

Either the router is still using IPV6 (locally) or NetworkManager is not configured to exclude DHCPv6 offers.

But since this is already solved, you may as well disable ipv6 globally in any possible way if you don't need it at all.

TL,DR. fe80::6666:b3ff:fe16:4b12 and 192.168.1.1 are the same host.

Last edited by lo1 (2018-06-23 16:55:58)

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