Middle_server_configuration.md

Middle server configuration guide

Note! Linux based operating system must be installed on the server.

1. Configuring firewall (iptables)

1.1 Forward proxy connections

Note! Set correct port and IP address of the server with proxy installed.

iptables -t nat -A PREROUTING -p tcp --dport 1337 -j DNAT --to-destination 127.0.0.1:1337 

iptables -t nat -A POSTROUTING -j MASQUERADE 

1.2 Forward VPN connections

Note! Set correct IP address of the server with VPN installed.

iptables -t nat -A PREROUTING -p tcp --dport 1723 -j DNAT --to-destination 127.0.0.1:1723

iptables -t nat -A PREROUTING -p gre -j DNAT --to-destination 127.0.0.1

iptables -t nat -A POSTROUTING -j MASQUERADE

iptables -A INPUT -p gre -j ACCEPT

iptables -A FORWARD -p gre -j ACCEPT

1.3 Save firewall rules

iptables-save

1.4 Save firewall rules permanently

apt-get install iptables-persistent

2. Configuring network

2.1 Enable IP forwarding and connection track helper

Open configuration file /etc/sysctl.conf and add the next lines:

net.ipv4.ip_forward=1
net.netfilter.nf_conntrack_helper=1

2.2 Apply the changes

sysctl -p

3. Configuring modules

3.1 Start PPTP module

modprobe ip_nat_pptp

3.2 Enable PPTP module on boot

Open configuration file /etc/modules and add the next line:

ip_nat_pptp