Clients on Orbi Wi-Fi receive an IPv6 default gateway from an Orbi unit

Thank you all for your replies.

I understand what you meant about the devices generating their own IPv6 addresses.

I just can't understand and fix the reason. While the Orbi is in AP mode, I can't use some features on some devices and as soon as I have it set to be in router mode, all flows nicely... to some extent...

Since the IPv6 doesn't add much to my day-to-day, I will leave it off on all the internet broadcasting devices.

What I am really trying to fix is to have the Orbi in AP mode to have the Firewalla controling the flows and help me with bufferbloat... and it seems I can't do it... even trying to use I is not helping me much. If only Netgear would include some sort of SQM in their software, it would be awesome...

Thanks again!

Yes, I can confirm the advice you are getting here on the link-local IPv6 address usage, GusTTavo​ . I have seen this in tcp dumps on my own network, where IPv6 is disabled on the router. To explain for you in more detail:

IPv6 link-local addresses are a normal part of networking and continue to work even when IPv6 is disabled on your router. Computers, phones, printers, and other devices on your network automatically create their own link-local IPv6 addresses, which typically begin with fe80::. These addresses allow devices to communicate directly with one another on the same local network without needing an Internet connection or IPv6 support from the router. They are used for basic networking tasks, such as finding other devices and exchanging information with them. Link-local addresses are limited to your local network and cannot be used to communicate directly with devices on the Internet.

When you disable IPv6 on your router, you are generally turning off its ability to provide IPv6 Internet connectivity and to help devices obtain IPv6 addresses for communicating beyond your local network. However, this does not turn off IPv6 on the individual computers, phones, and other devices connected to your network. Those devices can still use their link-local IPv6 addresses to communicate with one another. For example, two Macs on the same local network can communicate using their link-local IPv6 addresses even though IPv6 is disabled on the router.

The important point is that disabling IPv6 on your router does not disable IPv6 throughout your entire home network. Devices can still communicate locally using IPv6 without involving the router’s IPv6 routing functions to the outside world and back. Therefore, seeing IPv6 addresses beginning with fe80:: or IPv6 traffic when examining your network is perfectly normal, even if you have disabled IPv6 on your router. These addresses cannot be reached directly from the Internet and do not, by themselves, represent a security concern. In fact, it is generally best to leave IPv6 enabled on your computers and other devices because some operating system features and local networking services may depend on it, even when you use IPv4 for all your Internet traffic.

When in AP mode for Orbi, any and all network traffic gets pass thru the system. If IPv6 is being pass from the host router thru the Orbi system in AP mode, then Orbi just passes this along to any connected client. There's no way to block it while in AP mode. This would need to be done at the host router level if that's possible. While in AP mode Orbi system doesn't manage or host IPv6 services. Just passes thru. 

Disabling IPv6 on the Firewalla router does not mean that no IPv6 packets can exist on the home network (LAN).  It only means that the Firewalla does not participate using IPv6.

As StephenB​ pointed out, fe80::ca10:2fff:fe40:e8a5 is a link local address created by a device on the network that does support IPv6.  This link local address was not created by the Firewalla or by the Orbi.  Likewise, the other IPv6 addresses are coming from some device on the network.  The Orbi is not "advertising" them.

GusTTavo wrote:

My BGW320 is set to passthrough to my ORBI RBE770+2 satellites...

 
How do I stop the Orbi from advertising IPv6 in AP mode?

Passthrough normally means that the BGW320 is not routing.  Which normally would require the Orbi to be set up as a router, not AP.

Can you clarify the setup?

GusTTavo wrote:

fe80::ca10:2fff:fe40:e8a5

This is just a link-local address, and shouldn't be related to your issue.

GusTTavo wrote:

an fd2a:7f4:ca8c::/64 ULA prefix, and an IPv6 DNS server fd2a:7f4:ca8c::1.

What ipv6 DNS resolver are you seeing when directly connected to the BGW320?

Do you get a response when you ping the ULA?