Some clients not registering in NDP table with IPv6 through SLAAC or DHCPv6 on pfSense Plus

[tuanson84uk]

Hi everyone,

I'm running into an issue with IPv6 on my network that I can't quite figure out. I'm using pfSense with Router Advertisement set to Assisted mode and the DHCPv6 server enabled. Here's the situation:

• Some of my clients successfully obtain IPv6 addresses via SLAAC or DHCPv6, but they do not show up in the NDP table.
• Because these clients aren't registered in the NDP table, they can't access IPv6 sites and are not detected as using IPv6 at all.
• However, other clients on the same network are obtaining IPv6 addresses and do appear in the NDP table, allowing them to use IPv6 without issues.
• I've verified that ICMPv6 and Multicast are not being blocked on the network.

I’m puzzled as to why some devices are being properly registered in the NDP table while others are not. Has anyone else encountered this issue? What might be causing this inconsistency, and how can I ensure that all clients are registered in the NDP table correctly?

Any advice or troubleshooting tips would be greatly appreciated!

Thanks!

[JKnott]

@tuanson84uk

Are those clients Android devices? They don't work with DHCPv6. Any reason you need it? I've been running IPv6 on my home network for over 14 years and have never needed it.