Why does my NAS connect via IPv6 in Windows 11 24H2?
Applicable Products
QTS, QuTS Hero
Overview
When both IPv4 and IPv6 are enabled on a Windows 11 24H2 system, the operating system will prioritize IPv6 if the DNS server returns an IPv6 address for the destination hostname. This behavior is based on Microsoft's default address selection policy and is considered normal for dual-stack networks.
You may observe this behavior when accessing your NAS using its hostname (e.g., nasname.local) instead of an IP address. If the NAS has both IPv4 and IPv6 enabled, and the client system resolves an IPv6 address via DNS (including local fe80::/10 link-local addresses), the connection will default to IPv6.
Concept
The IPv6 address block fe80::/10 is reserved for link-local addresses. These addresses are automatically assigned to every network interface and are used for communication within the same local network segment. It is expected to see these addresses in internal networks.
If you see your NAS being accessed via an fe80:: address, this generally means that:
- The NAS and your PC are on the same local link.
- IPv6 is enabled and being prioritized by your OS.
- DNS resolution includes link-local IPv6 addresses.
- This is normal and low risk for internal network connections.
Recommendation
If you prefer your client to connect via IPv4:
- Use the NAS IPv4 address directly (e.g., \\192.168.xx.xx\).
- Disable IPv6 on the NAS. (This is disabled by default.)
