On my Debian Linux device, I have a USB-modem that is connected to the Internet. Its interface name is ppp0.
I also have a USB-wireless adapter, where I am hosting a Access Point. Its interface name is wlan0.
How to I route traffic between these interfaces, so that if my phone is connected to this AP, that I can access the Internet via ppp0?
EDIT 1: I tried setting up some routing, but does not seem to work. Here are the details:
# iptables --list-rules -P INPUT ACCEPT -P FORWARD ACCEPT -P OUTPUT ACCEPT -A FORWARD -i ppp0 -o wlan0 -m state --state RELATED,ESTABLISHED -j ACCEPT -A FORWARD -i wlan0 -o ppp0 -j ACCEPT # iptables --list-rules -t nat -P PREROUTING ACCEPT -P INPUT ACCEPT -P OUTPUT ACCEPT -P POSTROUTING ACCEPT -A POSTROUTING -o ppp0 -j MASQUERADE
EDIT 2 SOLVED: I was able to solve my problem. I was using the same subnet for wlan0 and ppp0. When using different subnets for wlan0 and ppp0, everything worked fine. I also found this article useful: http://elinux.org/RPI-Wireless-Hotspot