Setup VPN Pribadi dengan PPTP pada CentOS dan Ubuntu
Berikut ini adalah bagaimana cara membuat sebuah VPN dengan PPTP pada XEN VPS Linux Indonesia dengan menggunakan sitem operasi CentOS dan Ubuntu
Pengertian VPN :
A virtual private network (VPN) extends a private network across a public network, such as the Internet. It enables a computer to send and receive data across shared or public networks as if it is directly connected to the private network, while benefiting from the functionality, security and management policies of the private network. A VPN is created by establishing a virtual point-to-point connection through the use of dedicated connections, virtual tunneling protocols, or traffic encryptions. (source : wikipedia.org)
Pengertian PPTP:
The Point-to-Point Tunneling Protocol (PPTP) is a method for implementing virtual private networks. PPTP uses a control channel over TCP and a GRE tunnel operating to encapsulate PPP packets.
The PPTP specification does not describe encryption or authentication features and relies on the Point-to-Point Protocol being tunneled to implement security functionality. However, the most common PPTP implementation shipping with the Microsoft Windows product families implements various levels of authentication and encryption natively as standard features of the Windows PPTP stack. The intended use of this protocol is to provide security levels and remote access levels comparable with typical VPN products. (source: wikipedia.org)
langkah 1 : Instalasi PPTP
CentOS 6 x64:
rpm -i http://poptop.sourceforge.net/yum/stable/rhel6/pptp-release-current.noarch.rpm yum -y install pptpd
Ubuntu 12.10 x64:
apt-get install pptpd
Langkah 2 : Konfigurasi PPTP
Ubah file /etc/pptpd.conf lalu tambahkan baris berikut:
localip 10.0.0.1 remoteip 10.0.0.100-200
dimana localip adalah IP VPS anda dan remoteip adalah IP yang akan dipakai klien yang nantinya terkoneksi.
Lalu setelah itu tambahkan user dan password yang bisa melakukan keneksi terhadap server VPN dengan edit file /etc/ppp/chap-secrets
# Secrets for authentication using CHAP # client server secret IP addresses interpark pptpd rahasi *
langkah 3 : tambahkan DNS servers pada DNS servers pada /etc/ppp/options.pptpd
anda bisa menambahkan DNS google :
ms-dns 8.8.8.8 ms-dns 8.8.4.4
setelah itu jalankan PPTP dengan
service pptpd restart
Langkah 4 : Setup Forwarding
Ubah file /etc/sysctl.conf dan tambahkan baris berikut
net.ipv4.ip_forward = 1
untuk mengaktifkannya, jalankan perintah sysctl -p
Langkah 5 : Buat sebuah NAT rule untuk iptables
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE && iptables-save