This is interesting. We suffer from spurious connection losses since we
started with OBSD ipsec.
Do you have any details what caused your problem, and why setting
DPD-check-interval helped?


quoted text
> In our environnement (we manage openbsd tunnels to cisco 3030
> which is out of our scope) we debugged a strange problem when
> the connection goes down. The tunnels won't come back after a
> small link shutdown.
>
> The problem was Cisco 3030 was doing DPD check and not the OpenBSD.
>
> If it's the case for you too, you should add these lines to
> /etc/isakmpd/isakmpd.conf :
>
> --- isakmpd.conf ---
> [General]
> DPD-check-interval=     30
> --- isakmpd.conf ---