Openswan is an ipsec based vpn solution for the linux kernel. it can use the native ipsec stack as well as the klips kernel module. both ikev1 and ikev2 protocols are supported.

for support of the old-style klips ipsecx network interfaces a custom kernel module is needed.

this package contains source code for the openswan ipsec kernel module, which can be used with dkms so that local kernel images are automatically built and installed every time relevant kernel packages are upgraded.

kernel versions >= 2.6.23 no longer need to be patched to provide nat traversal support for klips.