In an IPv6 address, the symbol % represents a zone index, which is used to specify the scope or interface of the address. IPv6 addresses can be shared between multiple network interfaces, so in some cases, especially on multi-NIC devices, you may need to specify which interface to use;
The role of zone identifiers
Multi-interface environment
- When a device has multiple network interfaces (such as Ethernet, Wi-Fi, etc.), each interface may have the same link-local address (that is, an address that begins with
fe80::). Using zone identifiers can clearly specify which interface to use.
- When a device has multiple network interfaces (such as Ethernet, Wi-Fi, etc.), each interface may have the same link-local address (that is, an address that begins with
Avoiding ambiguity
- Using zone identifiers can avoid ambiguity when there are multiple identical addresses. For example, the
%15in the addressfe80::ec53:1e5f:ce40:8dc6%15specifies a specific interface, ensuring that the address is resolved correctly.
- Using zone identifiers can avoid ambiguity when there are multiple identical addresses. For example, the