[strongSwan] strongSwan 5.2+ disconects clients after 1 hour

[Dan Craciun]

Hi,

strongSwan 5.2.1 (also tested with 5.2.0 and 5.2.2) on Slackware 13.1.
L2TP/IPsec, using PSK with xl2ptd.

After initial successful connection, the client (Windows 7 or 8) tries
to rekey after ~1 hour and it fails.

The debug log is here: http://pastebin.com/akuAYEDn

/etc/ipsec.conf
conn vpnserver
  type=transport
  authby=secret
  rekey=yes
  lifetime=2h
  ikelifetime=4h
  leftprotoport=udp/l2tp
  right=%any
  rightprotoport=%any
  auto=add



Any ideas?

Thank you.

Best regards,
Dan Craciun