Routing problem when setting up shared access point

Product support
46

Okey I have found out what make that “Hotspot connected” symbol shown when connecting my phone to my device. It was the Network Manager connection.metered value on my wifi hotspot interface that was set as unknown. By setting the value to “no” will change the symbol to the regular “Wi-Fi network connected”.

I still have some intermittent problems with internet connection and I think the MTU value is the problem. My wwan0 connection (modem) got MTU set to 1430. By change MTU to 1400 on my wifi clients I can get it working.
As I understand the DHCP server can tell wifi clients to use a specific MTU value. How do I set this on my device? I can set 802-11-wireless.mtu to 1400 but the clients doesn’t care about it.

47

Got it working by alter the MSS (Maximum Segment Size) value of TCP SYN packets with:

iptables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o wwan0 -j TCPMSS --clamp-mss-to-pmtu

So, I guess I have to install iptables in the container and add this rule to it.