Sep 24, 2019
Jan 04, 2011 Debian/Jessie: Easiest way to connect to VPN (Ipsec) For connecting to an IPsec VPN as a client, vpnc is quite easy to install and use. Our Linux users use it to connect to our PfSense IPsec VPNs. For installing it: sudo apt-get install vpnc To configure it, for instance, an IPsec VPN with PSK+Xauth authentication: Abstract: This HowTo will cover the basic and advanced steps setting up a VPN using IPsec based on the Linux Kernels 2.6. Since there is a vast amount of documentation available for the Linux Kernel 2.4, this HowTo will concentrate on the new IPsec Features in the 2.6 kernel.
How to configure a Linux firewall to masquerade IPsec- and PPTP-based Virtual Private Network traffic, allowing you to establish a VPN connection without losing the security and flexibility of your Linux firewall's internet connection and allowing you to make available a VPN server that does not have
If you want to implement an IPsec-based VPN on Linux, please visit the Linux FreeS/WAN site. This is particularly recommended if you're considering setting up a PPTP-based VPN between two networks that are both behind Linux firewalls. IPsec is more secure and much better suited to this than PPTP. VPN PPP−SSH Mini−HOWTO - Linux Documentation Project FreeS/WAN is probably the best Linux ipsec implementation today. Although it can be very difficult to set up, especially for those who are not terribly familiar with networking, it is amazingly stable once it is working. You can find out more at the FreeS/WAN home page. VPN PPP−SSH Mini−HOWTO 2.3. Suggested Reading 4
By default, the Red Hat Enterprise Linux implementation of IPsec uses group 2 (or modp1024) of the Diffie-Hellman cryptographic key exchange groups. Group 2 uses a 1024-bit modular exponentiation that prevents attackers from decrypting previous IPsec transmissions even if a private key is compromised.
a patch to make IPsec, PPTP and SSH VPNs work through a Linux firewall with IP masquerade. Linux VPN Masquerade HOWTO Note that this is not required if the same machine does IPsec and masquerading, only if you want a to locate your IPsec gateway on a masqueraded network.