Matching IDs with selectors is fairly straightforward: they have to be equal. In the case of a Road Warrior connection, if an equal match is not found for the Peer's ID, and it is in the form of an IP address, a selector of %any will match the peer's IP address if IPV4 and %any6 will match a the peer's IP address if IPv6. Currently, the obsolete notation 0.0.0.0 may be used in place of %any.When using IKEv1 an additional complexity arises in the case of authentication by preshared secret: the responder will need to look up the secret before the Peer's ID payload has been decoded, so the ID used will be the IP address.