Amazon EC2 Ubuntu 12.04 - unable to route all traffic through OpenVPN [closed]

StackOverflow https://stackoverflow.com/questions/19161279

  •  30-06-2022
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Question

I'm trying to use OpenVPN on my remote Ubuntu 12.04 web server, but as soon as OpenVPN is running, I can't connect to the internet.

Befor starting OpenVPN, route says:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         ip-172-31-16-1. 0.0.0.0         UG    100    0        0 eth0
172.31.16.0     *               255.255.240.0   U     0      0        0 eth0

and after:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         10.200.4.1      128.0.0.0       UG    0      0        0 tun0
default         172.31.16.1     0.0.0.0         UG    100    0        0 eth0
10.200.4.0      *               255.255.252.0   U     0      0        0 tun0
128.0.0.0       10.200.4.1      128.0.0.0       UG    0      0        0 tun0
172.31.16.0     *               255.255.240.0   U     0      0        0 eth0
184.170.137.2   172.31.16.1     255.255.255.255 UGH   0      0        0 eth0

184.170.137.2 is the VPN. The OpenVPN HOWTO suggests to use

iptables -t nat -A POSTROUTING -s 10.200.4.0/22 -o eth0 -j MASQUERADE

which throws

sudo: unable to resolve host ip-172-31-26-178

(172.31.26.178 is the internal IP).

If I do the following, I can use the VPN for a single website: 

route add -net {website ip} netmask 255.255.255.255 gw 10.200.4.1 dev tun0
route del -net 0.0.0.0 netmask 128.0.0.0 dev tun0
route del -net 128.0.0.0 netmask 128.0.0.0 dev tun0

How can I change this to work for the whole web? Help is greatly appreciated.

Was it helpful?

Solution

Here is what the problem was. Connection to hidemyass is done by hma-vpn.sh script, you have to change 

#!/bin/sh
cat <<EOEO >> /tmp/hma-ipcheck.txt
 *******************************************
* *
* You are now connected to HMA Pro! VPN *
* *
 *******************************************

Checking new IP address...
EOEO
nohup /tmp/hma-ipcheck.sh >/dev/null 2>&1 >
rm /tmp/hma-routeup.sh
EOF

to 

#!/bin/sh
cat <<EOEO >> /tmp/hma-ipcheck.txt
 *******************************************
* *
* You are now connected to HMA Pro! VPN *
* *
 *******************************************

Checking new IP address...
EOEO
vpn_gw=\$(ip route | grep tun0 | grep 0.0.0.0 | cut -d" " -f3)
route del -net 0.0.0.0 gw {your-original-default-gateway}
route del -net 0.0.0.0 gw \$vpn_gw
route del -net 0.0.0.0 netmask 128.0.0.0 gw \$vpn_gw
route del -net 128.0.0.0 netmask 128.0.0.0 gw \$vpn_gw
route add default gw \$vpn_gw
echo "nameserver 208.67.222.222">/etc/resolv.conf
nohup /tmp/hma-ipcheck.sh >/dev/null 2>&1 >
rm /tmp/hma-routeup.sh
EOF`enter code here`

This will change your default gateway to be the vpn server. You can skip echo "nameserver 208.67.222.222">/etc/resolv.conf if your dns are accessible through the vpn

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