Arch Linux

jwesley

Member

Registered: 2012-10-16

Posts: 4

VPNC Routing and DNSMASQ

Environment

Arch with 2 network interfaces on a single host configured with iptables, dnsmasq, and vpnc. The LAN is masquerading behind an ISP's public IP.

• Router (Arch)

• Switch

• Cable Modem

• Desktop

Scenario

Establishing a VPN tunnel with vpnc from the router to the remote concentrator that's usable from the desktop on the LAN. I was able to accomplish this with iptables by forwarding packets from the LAN interface to the tunnel interface:

-A FORWARD -i enp2s0 -o tun0 -j ACCEPT

And then masquerading packets from the LAN to the tunnel:

-A POSTROUTING -s 10.0.0.0/27 -o tun0 -j MASQUERADE

Problem with this scenario is DNS from the desktop is not working. I think the issue is with how I'm handling DNS. I'm also not sure this is the ideal setup. Traffic appears to be split correctly, in that packets not destined for the VPN subnet correctly use the default GW to the ISP.

Does anyone have any experience with a similar situation?