IPv6 link-local addresses explained

IPv6 link-local addresses make sense alongside the way a host identifies its local network, neighbours and route to other networks. IPv4 depends on the address, prefix length and gateway; IPv6 also depends on address scope and Neighbor Discovery. One wrong value can leave local communication working while breaking access beyond the subnet.

How to check the network settings

Start with the interface address, prefix, routing table and default gateway. Check whether the destination belongs to the local prefix and whether a default route exists. Do not change a mask or gateway by guesswork; compare it with DHCP or network documentation and repeat the same test after one controlled change.

The detail that matters

IPv6 link-local addresses come from fe80::/10 and are meaningful only on the local link. Because the same link-local address can exist on different interfaces, operating systems may require a zone or interface identifier when you use one manually, especially for diagnostics and gateway references. For a calculation you can compare with the explanation above, use 2ip WHOIS/RDAP lookup.