I'm no guru on bridging, but I don't think you can bridge dissimilar devices.
I think what you want to do is simply forward an ip connection. This involves enabling ip-forwarding in the kernel and providing a default route in the routing table so your PDA can find the internet. It also involves MASQUERADING in the nat
table's POSTROUTING chain (using iptables
). You will also have to provide your PDA device with the addresses of your ISP's DNS servers.
The routing table is probably set up correctly when you establish the ppp
connection. This should also set up /etc/resolv.conf
with the correct DNS addresses. You need to get these addresses to you PDA either manually, or by setting up a DHCP server. (Warning: I have no experience with a PDA.)
For the rest you could:
iptables -t nat -A POSTROUTING -o ppp+ -j MASQUERADE
sysctl -w net.ipv4.ip-forward=1
You could add this to your rc.local
file, or if you already have a firewall setup, you could merge the iptables
command into that.