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@Lazar-Demin If you have ipv6 installed it will default a link local address on each interface. Same as 169.254.x.x ipv4 addresses. An easy test is to use ping 6 command:
ping6 -c 2 -i 4 -I wlp0s20f3 ff02::1
Where "wlp0s20f3" is the name of my notebook's interface and the ff02::1 is the link local "all nodes" address, like broadcast address (but that term upsets the ipv6 professors). It will respond with the ipv6 address of all nodes on link local. Here 's what's on my development network:
ping6 -c 2 -i 4 -I wlp0s20f3 ff02::1
ping6: Warning: source address might be selected on device other than: wlp0s20f3
PING ff02::1 (ff02::1) from :: wlp0s20f3: 56 data bytes
64 bytes from fe80::b06d:1d07:966:4c65%wlp0s20f3: icmp_seq=1 ttl=64 time=0.160 ms
64 bytes from fe80::feec:daff:fe31:e1c6%wlp0s20f3: icmp_seq=1 ttl=64 time=2.94 ms
64 bytes from fe80::8bb4:297b:abb:7968%wlp0s20f3: icmp_seq=1 ttl=64 time=3.27 ms
64 bytes from fe80::46d9:e7ff:feb8:53a7%wlp0s20f3: icmp_seq=1 ttl=64 time=3.54 ms
64 bytes from fe80::6ad7:9aff:fe02:b2b8%wlp0s20f3: icmp_seq=1 ttl=64 time=3.58 ms
64 bytes from fe80::c251:7eff:fe5d:7c73%wlp0s20f3: icmp_seq=1 ttl=64 time=3.58 ms
64 bytes from fe80::76ac:b9ff:fe4e:29db%wlp0s20f3: icmp_seq=1 ttl=64 time=3.58 ms
64 bytes from fe80::b6a3:82ff:fe4b:20b6%wlp0s20f3: icmp_seq=1 ttl=64 time=3.58 ms
64 bytes from fe80::f64d:30ff:fe6b:8b4a%wlp0s20f3: icmp_seq=1 ttl=64 time=3.59 ms
64 bytes from fe80::188a:822d:9b56:843c%wlp0s20f3: icmp_seq=1 ttl=64 time=3.93 ms
64 bytes from fe80::42a3:6bff:fec4:1d8e%wlp0s20f3: icmp_seq=1 ttl=64 time=4.24 ms
64 bytes from fe80::d8f4:6b58:8b5e:cd9f%wlp0s20f3: icmp_seq=1 ttl=64 time=73.7 ms
64 bytes from fe80::a2dc:4ff:fe2a:8411%wlp0s20f3: icmp_seq=1 ttl=64 time=181 ms
64 bytes from fe80::a91:15ff:fefe:8897%wlp0s20f3: icmp_seq=1 ttl=64 time=304 ms
64 bytes from fe80::10b7:9243:cdf4:873e%wlp0s20f3: icmp_seq=1 ttl=64 time=304 ms
64 bytes from fe80::b6fb:e4ff:fec9:3b8%wlp0s20f3: icmp_seq=1 ttl=64 time=308 ms
64 bytes from fe80::f29f:c2ff:fec5:9ab2%wlp0s20f3: icmp_seq=1 ttl=64 time=356 ms
64 bytes from fe80::f29f:c2ff:fe09:fe1%wlp0s20f3: icmp_seq=1 ttl=64 time=878 ms
64 bytes from fe80::b06d:1d07:966:4c65%wlp0s20f3: icmp_seq=2 ttl=64 time=0.081 ms
--- ff02::1 ping statistics ---
2 packets transmitted, 2 received, +17 duplicates, 0% packet loss, time 4004ms
rtt min/avg/max/mdev = 0.081/128.421/877.572/217.804 ms
You can see they all start with "fe80" which indicates these addresses are created by the Stateless Auto Address Configuration function of ipv6 (SLACC). So even if you set an ipv6 address on an interface ipv6 will still create the link local address.
There is a lot to ipv6, but this is one of the nice little features.