i am doing a site-to-site vpn experiment with two router.one is 3660(Ra).another is provided by other(Rb).if Ra initiates the negotiation, a new isakmp sa can be got but authentication fails.otherwise Rb is the initiator, the isakmp sa negotiation can be finished normally.i migrated the configurations of Rb to a 3640 router unchanged.the negotiation of the phase 1 exchange is finished normally without regard to the direction.Rb's provider assured their products were compatible with RFC2409 strictly.does Cisco have some private policies in the authentication during the phase 1 negotiation?
any help would be appreciated
