I have come across a situation where a transport mode connection between 2 peers for all intents and purposes appears to be up and in fact sends IKE information back and forth but does transfer other network traffic between the peers.
When investigating I found that during the time that network traffic between the peers was down 2 CHILD_SA objects were in place and each of these was only showing information as flowing in 1 direction (see bytes_i/bytes_o). test_tun[6370]: ESTABLISHED 3 hours ago, x.x.x.x[x.x.x.x]...y.y.y.y[y.y.y.y] test_tun[6370]: IKEv1 SPIs: 0fc1a23b9bc0c4d8_i f25712e162f02a05_r*, public key reauthentication in 20 hours test_tun[6370]: IKE proposal: AES_CBC_128/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1536 test_tun{5}: INSTALLED, TRANSPORT, ESP SPIs: c55656e9_i c61c84d3_o test_tun{5}: AES_CBC_256/HMAC_SHA1_96, 60284 bytes_i (2s ago), 0 bytes_o, rekeying in 23 seconds test_tun{5}: x.x.x.x/32 === y.y.y.y/32 test_tun{6682}: INSTALLED, TRANSPORT, ESP SPIs: c9daaf3f_i c6f11a51_o test_tun{6682}: AES_CBC_256/HMAC_SHA1_96, 0 bytes_i, 60972 bytes_o (2s ago), rekeying in 94 seconds test_tun{6682}: x.x.x.x/32 === y.y.y.y/32 The network is very stable and the tunnel was up and functioning for 2 days before this situation appeared. After 40 minutes of this the tunnel was function again (without intervention). test_tun[6370]: ESTABLISHED 3 hours ago, x.x.x.x[x.x.x.x]...y.y.y.y[y.y.y.y] test_tun[6370]: IKEv1 SPIs: 0fc1a23b9bc0c4d8_i f25712e162f02a05_r*, public key reauthentication in 20 hours test_tun[6370]: IKE proposal: AES_CBC_128/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1536 test_tun{6682}: INSTALLED, TRANSPORT, ESP SPIs: c9daaf3f_i c6f11a51_o test_tun{6682}: AES_CBC_256/HMAC_SHA1_96, 1360 bytes_i (0s ago), 63432 bytes_o (0s ago), rekeying in 56 seconds test_tun{6682}: x.x.x.x/32 === y.y.y.y/32 I have experienced this behavior before but had not noticed the fact that each CHILD_SA only had bytes in 1 direction. It should be noted that I had tested the same setup with the configuration option 'reauth=no' previously for 5 days without such a situation appearing. I then removed this option and after 2 days of testing I had the problem described above. I would appreciate any help if anyone has ideas on this. Thanks James _______________________________________________ Dev mailing list Dev@lists.strongswan.org https://lists.strongswan.org/mailman/listinfo/dev