Google Nest WiFi and IPV6 in bridge mode

[qd73]

Hi,

There is a bug on the Google Nest WiFi. Even when IPV6 is disabled, in bridge mode, all devices in my network are receiving ipv6 addresses. The Google Nest WiFi is broadcasting ICMPV6 Router Advertisement but it should not as it's in bridge mode with IPV6 disabled.

Model H2D

Version 14150.376.32

Am I the only one impacted ? How can I solve this ?

[MichaelP]

Hello @qd73 

When it's in bridge mode, it will retransmit all broadcast traffic from one side to the other, and this may include IPv6 autoconfiguration packets being sent by your "outer" router. Are your devices getting routable IPv6 addresses (something that doesn't start with "fe80::")? Basically, as a bridge, it won't be participating in IPv6 autoconfiguration of attached devices. If it were in router/NAT mode, it would be, and disabling IPv6 would stop it from doing that. That's my read on the situation, at least.

[qd73]

Hi @MichaelP .

In fact I can see RA packets coming from the WiFi router itself. If I configure my iptable firewall to block incoming ipv6 packets from the router, it's working fine.

The announced prefix is 

   inet6 fde7:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx/64 scope global deprecated dynamic mngtmpaddr noprefixroute
       valid_lft 1610sec preferred_lft 0sec

And if I don't block packets I get a lot of this in the syslog :

Jun 11 14:57:37 computer avahi-daemon[3439554]: Registering new address record for fde7:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx on enp0s25.*.
Jun 11 14:57:38 computer avahi-daemon[3439554]: Withdrawing address record for fde7:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx on enp0s25.

Which cause my browser to display regularly ERR_NETWORK_CHANGED

[MichaelP]

The "fde7" prefix is part of the IPv6 "Unique Local Address (ULA)" space (fc00::/7). These are akin to IPv4 addresses like 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16.

Are you sure this is coming from the bridge-mode Google WiFi unit and not from the your actual router? 

[qd73]

I am pretty sure. When I shut the port connected to the Google Wifi, the prefix is not here anymore and I don't have disconnection anymore.

[MichaelP]

Strange. So, just to make sure I understand your current setup, you have a non-Google router that feeds an Ethernet switch. The switch then connects computers as well as one Google WiFi unit that's in bridge mode. When the Google WiFi unit is connected, you get fde7 IPv6 advertisements. Do I have that right?

[qd73]

Yes, @MichaelP , exactly.

I have OpenWrt that acts as gateway on the same VLAN as Google WiFi and my laptop, all connect on a switch.

[MichaelP]

Ok, thanks. I'm going to "escalate" this in hopes it can get to the right place. In the mean time, could you also report it through the Google Home app using the "Feedback" feature? That will collect a bit of log data that may be useful. One last thing, though I don't think it will matter: which Ethernet port are you connecting to on the bridge-mode Google WiFi unit? Globe / WAN or <-> / LAN?

[qd73]

@MichaelP Sure I will do that. I connect the unit using the WAN port.

I also captured some RA broadcasted by the Google Wifi if needed.

[LovelyM]

Hello everyone,

@MichaelP, I appreciate your assistance here.

@qd73, thanks for bringing this up. We'd appreciate it if you can send feedback about this issue that you're getting using the Google Home app so our product team will be able to review the crash log reports. In that way, they'll be able to take a closer look into this. Check out this link for more information.

Let us know if you have additional questions or concerns; otherwise, I'll close the thread after 24 hours.

Best regards,
Lovely

[qd73]

Hi @LovelyM ,

The issue is still there. I already sent feedback on the home app.

[LovelyM]

Hey qd73,

Sorry for the late revert. We don't have any news to share on when a fix for this will be available, so please keep an eye out for updates. 

Thanks, 
Lovely

[LovelyM]

Hello qd73, 

I know it has been a while, but I want to ensure that everything is covered on your end. If you have other questions or concerns, feel free to tell me, as I would love to help.

Sincerely, 
Lovely

[qd73]

Hi,

My device has been replaced and now it seems to perform correctly!

[Alex_S]

Hi there,

We’re glad to hear that this has been sorted out! Let us know if there’s anything else we can help you with. We’ll be more than happy to assist you.

Cheers,
Alex