root@cp-strongswan:~# ipsec up vpn_smb
initiating IKE_SA vpn_smb[1] to X.X.X.X
generating IKE_SA_INIT request 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) N(FRAG_SUP) N(HASH_ALG) N(REDIR_SUP) ]
sending packet: from 10.182.0.12[500] to X.X.X.X[500] (1236 bytes)
received packet: from X.X.X.X[500] to 10.182.0.12[500] (449 bytes)
parsed IKE_SA_INIT response 0 [ SA KE No N(NATD_S_IP) N(NATD_S_IP) N(NATD_S_IP) N(NATD_S_IP) N(NATD_S_IP) N(NATD_D_IP) CERTREQ ]
selected proposal: IKE:AES_CBC_256/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024
local host is behind NAT, sending keep alives
received cert request for "O=00:1C:7F:B1:9C:48..ng4uc4"
received 1 cert requests for an unknown ca
sending cert request for "O=00:1C:7F:B1:9C:48..ng4uc4"
no IDi configured, fall back on IP address
establishing CHILD_SA vpn_smb{1}
generating IKE_AUTH request 1 [ IDi N(INIT_CONTACT) CERTREQ IDr CPRQ(ADDR DNS) SA TSi TSr N(MOBIKE_SUP) N(NO_ADD_ADDR) N(EAP_ONLY) N(MSG_ID_SYN_SUP) ]
sending packet: from 10.182.0.12[4500] to X.X.X.X[4500] (412 bytes)
received packet: from X.X.X.X[4500] to 10.182.0.12[4500] (76 bytes)
parsed IKE_AUTH response 1 [ N(INVAL_SYN) ]
received INVALID_SYNTAX notify error
establishing connection 'vpn_smb' failed
root@cp-strongswan:~#