Comment 3 for bug 2007682

The problem happens when the parser needs a second pass to find all the interfaces. It doesn't check if the values are already in their lists.

The problem is not limited to the DNS entries.

Here is another example:

network:
  bonds:
    aggi:
      routing-policy:
        - table: 1
          from: 1.2.3.4
      nameservers:
        addresses:
        - 8.8.8.8
        search:
        - example.com
      interfaces:
      - ens3f0
  ethernets:
    ens3f0: {}

The .netdev file will look like this:

[Match]
Name=aggi

[Network]
LinkLocalAddressing=ipv6
DNS=8.8.8.8
DNS=8.8.8.8
Domains=example.com example.com
ConfigureWithoutCarrier=yes

[RoutingPolicyRule]
From=1.2.3.4
Table=1

[RoutingPolicyRule]
From=1.2.3.4
Table=1