Scoped Addresses

IPv6 uses a category of addresses called link-local addresses that are used solely on a local subnet. Every IPv6 VLAN must have at least one link-local address. If a global IP address is configured on a VLAN that has no link-local address, one is assigned automatically by the switch. The link-local addresses start with the prefix fe80::/64. As a result, a switch can have the same link local address assigned to different VLANs, or different neighbors on different links can use the same link local address. Because of this, there are cases where you need to specify an address and a VLAN/tunnel to indicate which interface to use. For those cases, you can indicate the interface by using a scoped address. To scope the address, append the VLAN/tunnel name to the end of the address, separated by a percent sign (%). For example, to indicate the link local address fe80::2 on VLAN finance, use the following form:
fe80::2%finance

Scoped addresses also appear in the output of display commands.