# tcpdump -nvvr /var/run/isakmpd.pcap
tcpdump: WARNING: snaplen raised from 96 to 65536
tcpdump: WARNING: compensating for unaligned libpcap packets
14:01:57.892590 87.97.101.61.61390 > 80.249.169.70.500: [udp sum ok] isakmp v1.0 exchange ID_PROT
        cookie: d6526547c14c5930->0000000000000000 msgid: 00000000 len: 184
        payload: SA len: 56 DOI: 1(IPSEC) situation: IDENTITY_ONLY
            payload: PROPOSAL len: 44 proposal: 1 proto: ISAKMP spisz: 0 xforms: 1
                payload: TRANSFORM len: 36
                    transform: 0 ID: ISAKMP
                        attribute ENCRYPTION_ALGORITHM = AES_CBC
                        attribute HASH_ALGORITHM = SHA
                        attribute AUTHENTICATION_METHOD = RSA_SIG
                        attribute GROUP_DESCRIPTION = MODP_1024
                        attribute LIFE_TYPE = SECONDS
                        attribute LIFE_DURATION = 3600
                        attribute KEY_LENGTH = 256
        payload: VENDOR len: 20 (supports v1 NAT-T, draft-ietf-ipsec-nat-t-ike-00)
        payload: VENDOR len: 20 (supports v2 NAT-T, draft-ietf-ipsec-nat-t-ike-02)
        payload: VENDOR len: 20 (supports v3 NAT-T, draft-ietf-ipsec-nat-t-ike-03)
        payload: VENDOR len: 20 (supports NAT-T, RFC 3947)
        payload: VENDOR len: 20 (supports DPD v1.0) [ttl 0] (id 1, len 212)
14:01:57.893110 80.249.169.70.500 > 87.97.101.61.61390: [udp sum ok] isakmp v1.0 exchange ID_PROT
        cookie: d6526547c14c5930->5bba656c7f64d06e msgid: 00000000 len: 184
        payload: SA len: 56 DOI: 1(IPSEC) situation: IDENTITY_ONLY
            payload: PROPOSAL len: 44 proposal: 1 proto: ISAKMP spisz: 0 xforms: 1
                payload: TRANSFORM len: 36
                    transform: 0 ID: ISAKMP
                        attribute ENCRYPTION_ALGORITHM = AES_CBC
                        attribute HASH_ALGORITHM = SHA
                        attribute AUTHENTICATION_METHOD = RSA_SIG
                        attribute GROUP_DESCRIPTION = MODP_1024
                        attribute LIFE_TYPE = SECONDS
                        attribute LIFE_DURATION = 3600
                        attribute KEY_LENGTH = 256
        payload: VENDOR len: 20 (supports OpenBSD-4.0)
        payload: VENDOR len: 20 (supports v2 NAT-T, draft-ietf-ipsec-nat-t-ike-02)
        payload: VENDOR len: 20 (supports v3 NAT-T, draft-ietf-ipsec-nat-t-ike-03)
        payload: VENDOR len: 20 (supports NAT-T, RFC 3947)
        payload: VENDOR len: 20 (supports DPD v1.0) [ttl 0] (id 1, len 212)
14:01:57.925943 87.97.101.61.61390 > 80.249.169.70.500: [udp sum ok] isakmp v1.0 exchange ID_PROT
        cookie: d6526547c14c5930->5bba656c7f64d06e msgid: 00000000 len: 376
        payload: KEY_EXCH len: 132
        payload: NONCE len: 20
        payload: CERTREQUEST len: 148
        payload: NAT-D len: 24
        payload: NAT-D len: 24 [ttl 0] (id 1, len 404)
14:01:57.927946 80.249.169.70.4500 > 87.97.101.61.4500: [udp sum ok] udpencap: isakmp v1.0 exchange ID_PROT
        cookie: d6526547c14c5930->5bba656c7f64d06e msgid: 00000000 len: 376
        payload: KEY_EXCH len: 132
        payload: NONCE len: 20
        payload: CERTREQUEST len: 148
        payload: NAT-D len: 24
        payload: NAT-D len: 24 [ttl 0] (id 1, len 408)