[strongSwan] strongswan-5.1.1 with 4.xx, tunnel pb

[Volker Rümelin]

Hello Serge,

> Dec 29 22:23:19 karma charon: 11[ENC] generating IKE_AUTH response 1 [ IDr CERT AUTH SA TSi TSr N(AUTH_LFT) N(MOBIKE_SUP) N(ADD_4_ADDR) N(ADD_4_ADDR) N(ADD_6_ADDR) ]
> Dec 29 22:23:19 karma charon: 11[NET] sending packet: from 192.168.4.10[4500] to 192.168.4.87[62698] (1612 bytes)

This packet was a large packet and was sent as two UDP fragments. One or possibly both fragments were
dropped on the route to the other side.

>   
> Dec 29 22:23:23 karma charon: 12[NET] received packet: from 192.168.4.87[62698] to 192.168.4.10[4500] (1500 bytes)
> Dec 29 22:23:23 karma charon: 12[ENC] parsed IKE_AUTH request 1 [ IDi CERT CERTREQ IDr AUTH SA TSi TSr N(MOBIKE_SUP) N(NO_ADD_ADDR) N(MULT_AUTH) ]
> Dec 29 22:23:23 karma charon: 12[IKE] received retransmit of request with ID 1, retransmitting response
> Dec 29 22:23:23 karma charon: 12[NET] sending packet: from 192.168.4.10[4500] to 192.168.4.87[62698] (1612 bytes)
> Dec 29 22:23:30 karma charon: 09[NET] received packet: from 192.168.4.87[62698] to 192.168.4.10[4500] (1500 bytes)

I can see this is still your setup with the NAT router. Most likely you have a problem with this router and
you should try to fix the router.

Regards,
Volker