FAQ

FAQ

( we will sort this in categories once we have more )

Which IKE Exchange modes does libreswan support?

The IANA Registry lists all official Exchange Modes. There are a few IKEv1 Modes that are very common despite never gotten past the draft stage.

Supported:

• IKEv2 (PSK, raw RSA, X509)
• IKEv1 Main Mode (PSK, raw RSA, X509)
• IKEv1 Aggressive Mode (PSK, raw RSA, X509)
• IKEv1 XAUTH/RSA and XAUTH/PSK with ModeConfig (aka "Cisco IPsec mode")

Not supported

• IKEv2 CP mode (planned, not yet implemented)
• IKEv1 Revised Mode
• IKEv1 Hybrid Mode (aka "Mutual Group Authentication") although there is some unmaintained contributed code

Module unloading error on shutdown or restart: Module esp4 is in use

A common error to see is:

ERROR: Module xfrm4_mode_tunnel is in use
ERROR: Module esp4 is in use
FAILURE to unload NETKEY esp4/esp6 module

This has been fixed in libreswan-3.9. Please upgrade