OpenVPN & Zoiper on iPhone - multiple IPs being used

AndyInNYC

I have a rather generic server configuration on RentPBX for our phone system and would like to allow users to connect via Zoiper (SIP phone for iPhone) and OpenVPN.

The phone client connects to the server and Zoiper registers using the VPN IP. However, when a call is made the server's call logs indicate that both the VPN IP and the phone's IP are both being used. Because of that, the phone gets disconnected after 10 seconds.

The server's conf file looks like this:

local RENTPBXIP
port 1194
proto udp
dev tun
daemon
persist-tun
persist-key
cipher BF-CBC
tls-server
mode server
server 10.11.12.0 255.255.255.0
push "route 10.2.1.0 255.255.255.0"
push "dhcp-option DNS 10.2.1.1"
keepalive 20 60
client-to-client
duplicate-cn
comp-lzo
verb 3
ca /etc/openvpn/ca.crt
cert /etc/openvpn/server.crt
key /etc/openvpn/server.key
dh /etc/openvpn/dh1024.pem
log-append /etc/openvpn/openvpn.log

I admit that I don't know what several of those lines do, but it was the 'recipe' i followed.

The phone's conf file looks like this:

client
persist-tun
persist-key
cipher BF-CBC
auth SHA1
tls-client
ns-cert-type server
remote RENTPBXIP
nobind
port 1194
proto udp
dev tun
comp-lzo
verb 3
ca /config/openvpn/keys/ca.crt
cert /config/openvpn/keys/client.crt
key /config/openvpn/keys/client.key

I can post the cli output from the asterisk PBX, but I'm not sure it matters - the PBX should only see the VPN IP - but it doesn't.

Any help from the gurus?

Andrew

Traffic

Perhaps your problem is related to this:
http://ipv6.com/articles/nat/NAT-In-Depth.htm

AndyInNYC

NAT shouldn't be an issue, though. Since the VPN connects to the internal network 10.11.12.x NAT isn't (shouldn't be) needed.

The Zoiper extension should be seen as completely local - but is obviously not.

Thanks for your response. I'm hopeful someone knows what my issue is.

Andrew

daveymg

I bashed my head against a wall for hours trying to solve a similar issue with Zoiper on Android sending the public ip as the source address across an openvpn link. In the end I tried a different voip client (Mizudroid) and the voip link over Openvpn worked perfectly.

I'm using Freepbx with Openvpn and Shorewall firewall on the server. Shorewall logging was showing packets from Zoiper arriving on the local (not vpn) interface with the public ip as the source address. The traffic must have been traveling over the vpn though as Zoiper didn't know the server's public ip.