tunnel devices with OpenSSH > 7.1

[openssh@mb.sy.gs]

Hello,

I have a strange situation using tunnel devices with OpenSSH on Debian. I've setup a new machine with OpenSSH 7.3p1. It works fine, but if I try to use a tunnel device with an OpenSSH client newer than 7.1 (tried with 7.2 and 7.3) the tunnel is not working. If I enable debug messages, configuring the devices is giving the following error message

# ifconfig tun1 10.1.1.1 pointtopoint 10.1.1.2
debug2: channel 0: write failed
debug2: channel 0: close_write
debug2: channel 0: chan_shutdown_write: shutdown() failed for fd 5: Socket operation on non-socket
debug2: channel 0: output open -> closed

The OpenSSH server (7.3p1) can be used with older clients fine but the recent clients (7.2/7.3) it can be used with tunneling devices against older OpenSSH servers, too.

It seems to be that there is a strange problem with tunnel devices if client and server are 7.2/7.3.

I use all packages from the Debian unstable repositories (amd64).

It would be nice to get any hint to solve this issue.

Thanks in advance!

Micha