racoon speaks IKE (ISAKMP/Oakley) key management protocol, to establish IPsec security association with other hosts. This is based on KAME racoon, with some enhancements such as NAT-Traversal (needs a kernel patch), hybrid authentication, ISAKMP mode config, RADIUS support, IKE fragmentation and others. Ipsec-tools' racoon is able to act as a VPN server for the Cisco VPN client using hybrid authentication.