Hi!
I performed some tests with ipfire and the Windows VPN client (for the rekey=no issue). I usually use short-time VPN connections (<3 hours), so I did not recognize any problems.
During the tests, I did not find any configuration that allowed me a stable VPN connection, all connections drop after 3-4 hours (IKE re-negotiation, CHILD_SA re-negotiation works fine). The problem could also be located in one of the used routers... If you have any suggestion on what configuration I should test as well, please let me know.
My default configuration (1st try): conn WinAndroidVPN left=%defaultroute leftsubnet=0.0.0.0/0 leftfirewall=yes lefthostaccess=yes leftallowany=yes leftcert=/var/ipfire/certs/hostcert.pem ike=aes256-sha1-modp1024! esp=aes256-sha1! right=%any keyexchange=ikev2 compress=yes dpdaction=clear dpddelay=30s auto=add rightsourceip=%dhcp ikelifetime=4h lifetime=2h keylife=8h rightcert=/var/ipfire/certs/WinAndroidVPNcert.pem
The protocol for this config is located here: http://pastebin.com/iXjjp71R
2nd try changes: ikelifetime=4h lifetime=90m The protocol for the 2nd config is located here: http://pastebin.com/xyarBvub
3rd try changes: rekey=no ikelifetime=4h lifetime=2h The protocol for the 3rd config is located here: http://pastebin.com/jmPNzxUX
So, sorry, I was not able to find a stable connection and have no suggestion on how to change the default config such that a stable connection with Windows 7/8.1 is possible.
Best regards, Wolfgang