> Here is the configuration I used between 2 peers > ike esp tunnel \
Interesting. Thanks for that, and for your help. I now seem to be able to get a flow going but not traffic (e.g. with the below I cannot ping). I'm sure I'm missing something obvious, but I think I need that second pair of eyes as I've been working on this problem so long ! HOST A (10.0.0.1) : -- ping 172.16.11.170 PING 172.16.11.170 (172.16.11.170): 56 data bytes 64 bytes from 172.16.11.170: icmp_seq=0 ttl=255 time=0.251 ms 64 bytes from 172.16.11.170: icmp_seq=1 ttl=255 time=0.336 ms --ipsec.conf : ike esp tunnel \ from 10.0.0.1 to 10.0.0.2 local 172.16.11.169 peer 172.16.11.170 \ main auth hmac-sha1 enc aes group grp5 \ quick auth hmac-sha1 enc aes group grp5 \ psk OpenBSD -- ipsecctl -s all FLOWS: flow esp in from 10.0.0.2 to 10.0.0.1 peer 172.16.11.170 srcid 172.16.11.169/32 dstid 172.16.11.170/32 type use flow esp out from 10.0.0.1 to 10.0.0.2 peer 172.16.11.170 srcid 172.16.11.169/32 dstid 172.16.11.170/32 type require SAD: esp tunnel from 172.16.11.169 to 172.16.11.170 spi 0x457e29e4 auth hmac-sha1 enc aes tcpmd5 from 172.16.11.169 to 172.16.11.170 spi 0x5ebc181a tcpmd5 from 172.16.11.170 to 172.16.11.169 spi 0xa8496b5c esp tunnel from 172.16.11.170 to 172.16.11.169 spi 0xbb35f85d auth hmac-sha1 enc aes -- isakmpd -Kvd 114001.702446 Default isakmpd: phase 1 done: initiator id 172.16.11.170, responder id 172.16.11.169, src: 172.16.11.169 dst: 172.16.11.170 114001.793818 Default isakmpd: quick mode done: src: 172.16.11.169 dst: 172.16.11.170 114022.266040 Default transport_send_messages: giving up on exchange peer-172.16.11.170-local-172.16.11.169, no response from peer 172.16.11.170:500 HOST B (10.0.0.2) : -- ping 172.16.11.169 PING 172.16.11.169 (172.16.11.169): 56 data bytes 64 bytes from 172.16.11.169: icmp_seq=0 ttl=255 time=0.336 ms 64 bytes from 172.16.11.169: icmp_seq=1 ttl=255 time=0.220 ms --ipsec.conf : ike esp tunnel \ from 10.0.0.2 to 10.0.0.1 local 172.16.11.170 peer 172.16.11.169 \ main auth hmac-sha1 enc aes group grp5 \ quick auth hmac-sha1 enc aes group grp5 \ psk OpenBSD --ipsecctl -s all FLOWS: flow esp in from 10.0.0.1 to 10.0.0.2 peer 172.16.11.169 srcid 172.16.11.170/32 dstid 172.16.11.169/32 type use flow esp out from 10.0.0.2 to 10.0.0.1 peer 172.16.11.169 srcid 172.16.11.170/32 dstid 172.16.11.169/32 type require SAD: esp tunnel from 172.16.11.169 to 172.16.11.170 spi 0x457e29e4 auth hmac-sha1 enc aes esp tunnel from 172.16.11.170 to 172.16.11.169 spi 0xbb35f85d auth hmac-sha1 enc aes tcpmd5 from 172.16.11.170 to 172.16.11.169 spi 0xe62273b9 tcpmd5 from 172.16.11.169 to 172.16.11.170 spi 0xf286fa8f --isakmpd -Kvd 123955.361080 Default attribute_unacceptable: ENCRYPTION_ALGORITHM: got AES_CBC, expected 3DES_CBC 123955.361154 Default message_negotiate_sa: no compatible proposal found 123955.361181 Default dropped message from 172.16.11.169 port 500 due to notification type NO_PROPOSAL_CHOSEN 124001.827314 Default isakmpd: phase 1 done: initiator id 172.16.11.170, responder id 172.16.11.169, src: 172.16.11.170 dst: 172.16.11.169 124001.922104 Default isakmpd: quick mode done: src: 172.16.11.170 dst: 172.16.11.169