Ok I know this sounds crazy but it’s all about Linux and iptables all the way
I’m using a rooted android phone as a VPN router to keep confidential traffic separated between networks
A and B are in the same network, B provides a separate network for C
Device A: Linux ip 192.168.15.32 wlan0 Device B: rooted Android phone with Termux and VPN Hotspot wlan0 ip 192.168.15.21 wlan1 ip 192.168.38.173
Device C: Windows 10 with RDP wlan1 ip 192.168.15.176
I’ve tried the following
A:
sudo ip route add 192.168.38.0/24 via 192.168.15.21 dev enp1s0
B:
Termux, su:
sysctl -w net.ipv4.ip_forward=1
iptables -t nat -A POSTROUTING -s 192.168.38.0/24 -o wlan0 -j MASQUERADE
iptables -A FORWARD -i wlan0 -o wlan1 -s 192.168.15.0/24 -d 192.168.38.0/24 -j ACCEPT
iptables -A FORWARD -i wlan1 -o wlan0 -s 192.168.38.0/24 -d 192.168.15.0/24 -j ACCEPT
C: default route via 192.168.38.173 metric 1
C is solely seeing the internet from B’s VPN, and can even access wlan0’s router, meaning it has access to its internal network. C can ping B, B can ping C
B can ping A and C
A can ping B, but not C, which also means no RDP access
What am I missing ?
Can you post
ip routput.Is your android being used as the modem/tether for device A? (If so adding route 192.168.38.0/24 via _gateway and _gateway dev x0 proto static scope link should allow it to reach C)
If using network manager just use the GUI to add the one line in routes. 192.168.38.0 24 yourgateway - it will do the metric on its own.
What are the gateway addresses?
You’d need to add a route from c to a as well, I believe, but I haven’t used windows in forever.
(The above is what I’ve had to do to get a machine behind an android to ping my other devices.)
ip r
default via 192.168.15.1 dev enp3s0 proto dhcp src 192.168.15.32 metric 100 192.168.15.0/24 dev enp3s0 proto kernel scope link src 192.168.15.32 metric 100 192.168.38.0/24 via 192.168.15.21 dev enp3s0