RubenPortier
Occasional Visitor
I've been using two AC-66U routers in Access Point (AP) mode, both of which are connected via UTP cable to a simple 1 Gbit switch connected to my pfSense box. I have IPv6 enabled on the pfSense router, and it's distributing IPv6 address to all my LAN devices using Stateless Autoconf. All my clients are able to obtain an IPv6 address, which is working fine.
My server (build up from older computer components) is running Ubuntu 16.10 which is used for virtualisation. It's running multiple guests (virtual machines) which all have a static IPv6 as a static IPv4 address. The problem I've been having is that whenever I have a wireless device trying to make a connection (ping, ssh etc.) to one of those guests or even the host (the server itself) it suddenly fails. All servers (host and guests) are having this issue on different timings. It can happen right after the host is booted, but mostly is about 1 - 10 mins. (can take longer). So I can be able to ping guest1, but guest2 would be unavailable. The servers itself are still able to make connections to any IP address except the wireless devices in the house (LAN). I can also still reach the servers from outside the LAN (remote location) and from any wired LAN connection. One very odd thing that I found is whenever I ping one of the servers over it's local IPv4 address, the IPv6 connection suddenly starts working again, for that particular server.
I went into deeper research and found out that the server is still getting a neighbour solicitation from the wireless device. It going for the device, through the wireless router (AP) until it reaches the server. The server is responding with a neighbour advertisement, but this advertisement cannot be found on the AP. Note I'm using tcpdump icmp6 on all devices to see this traffic. I've monitored all interfaces on the AP but none of them seem to get the advertisement de server is sending. This leads me to believe this is an issue with the firmware on the AC-66U routers, as both of them have this issue. I've tried a different AP (an old Apple AirPort Express), which kept on working fine without any issues. I've reached out to the Merlin-WRT forums, but none seems to reply on my topic. I've also tried many different forums but also no responses or nothing helpful.
I do not want to just throw away these expensive routers, as they both are capable of delivering a very good and stable Wi-Fi connection. But I hate having to deal with this issue every time I want to connection to one of the servers using my Macbook Pro, which is connection using Wi-Fi most of its time. I don't mind running some extra tests if you'd like me to. Also, don't mind asking for more information. I've been searching the web all over for this, but I couldn't find anything similar. It might be related to MLD snooping of some sort, which is IGMP snooping for IPv6 if I'm not wrong. Also note that the issue is not immediately active, the servers can be pingable over IPv6 locally for a short while, and then all of the sudden some of them stop working over Wi-Fi.
My server (build up from older computer components) is running Ubuntu 16.10 which is used for virtualisation. It's running multiple guests (virtual machines) which all have a static IPv6 as a static IPv4 address. The problem I've been having is that whenever I have a wireless device trying to make a connection (ping, ssh etc.) to one of those guests or even the host (the server itself) it suddenly fails. All servers (host and guests) are having this issue on different timings. It can happen right after the host is booted, but mostly is about 1 - 10 mins. (can take longer). So I can be able to ping guest1, but guest2 would be unavailable. The servers itself are still able to make connections to any IP address except the wireless devices in the house (LAN). I can also still reach the servers from outside the LAN (remote location) and from any wired LAN connection. One very odd thing that I found is whenever I ping one of the servers over it's local IPv4 address, the IPv6 connection suddenly starts working again, for that particular server.
I went into deeper research and found out that the server is still getting a neighbour solicitation from the wireless device. It going for the device, through the wireless router (AP) until it reaches the server. The server is responding with a neighbour advertisement, but this advertisement cannot be found on the AP. Note I'm using tcpdump icmp6 on all devices to see this traffic. I've monitored all interfaces on the AP but none of them seem to get the advertisement de server is sending. This leads me to believe this is an issue with the firmware on the AC-66U routers, as both of them have this issue. I've tried a different AP (an old Apple AirPort Express), which kept on working fine without any issues. I've reached out to the Merlin-WRT forums, but none seems to reply on my topic. I've also tried many different forums but also no responses or nothing helpful.
I do not want to just throw away these expensive routers, as they both are capable of delivering a very good and stable Wi-Fi connection. But I hate having to deal with this issue every time I want to connection to one of the servers using my Macbook Pro, which is connection using Wi-Fi most of its time. I don't mind running some extra tests if you'd like me to. Also, don't mind asking for more information. I've been searching the web all over for this, but I couldn't find anything similar. It might be related to MLD snooping of some sort, which is IGMP snooping for IPv6 if I'm not wrong. Also note that the issue is not immediately active, the servers can be pingable over IPv6 locally for a short while, and then all of the sudden some of them stop working over Wi-Fi.
