No certificate was found and reduced MTU

[Sheng Yu]

Hi all,

Recently, I have noticed that some clients can not connect (should be
iOS and OS X).

ocserv[2614]: worker:  tlslib.c:378: no certificate was found
ocserv[2614]: sec-mod: initiating session for user 'User' (session: HqLQN)
ocserv[2613]: main[User]: x.x.x.x:xxxxx new user session
ocserv[2613]: main[User]: x.x.x.x:xxxxx user logged in
ocserv[2790]: worker[User]: x.x.x.x:xxxxx worker-vpn.c:1048: GnuTLS
error (at worker-vpn.c:1048): The TLS connection was non-properly
terminated.
ocserv[2613]: main[User]: x.x.x.x:xxxxx user disconnected
ocserv[2614]: sec-mod: temporarily closing session for User (session: HqLQN)
ocserv[2613]: main: x.x.x.x:xxxxx: too short UDP packet

It was worked, and I do not have to modify any configuration.
All software are updated.
gnutls 3.4.3
ocserv 0.10.6


Another problem,
I noticed same clients sometimes MTU will be reduced to less than 200,
this what happened? MTU is greater than 1300 at the beginning
connection.

Are these two issues related?

Thanks.