IP Forwarding for Android

Android clients in a Staex MCC network rely on the parent node for both traffic routing and as a default gateway. The parent node must be configured to forward IP packets between the Android client and the rest of the MCC network.

Create a sysctl configuration file to enable IPv4 forwarding persistently:

echo "net.ipv4.ip_forward=1" | sudo tee /etc/sysctl.d/01-ip-forward.conf
sudo sysctl -w net.ipv4.ip_forward=1

The first command persists the setting across reboots; the second applies it immediately.

Install iptables-persistent to manage firewall rules that survive reboots, then add NAT and filter rules for the MCC tunnel interface:

sudo apt-get install iptables-persistent

Add NAT masquerading for traffic leaving the mcc0 interface, and appropriate FORWARD chain rules to allow traffic between the Android client and the MCC network.

Test your new rules with iptables-apply to ensure they work correctly before committing them. If the rules cause connectivity problems, iptables-apply will automatically revert after a timeout. Once confirmed, enable the iptables service to load the rules at boot.