VPN MTU limit breaks ssh connection to openssh 6.2p2 server

[Ernst Kratschmer]

Dear openssh developer, 

I want to use a Win7 client with putty to access a Linux host running an 
openssh 6.2p2 through a VPN connection. These connection worked relatively 
flawless with  all versions of openssh up until openssh 6.1p1. Since the 
openssh 6.2p2 upgrade the ssh connection fail consistently with a message: 
Network error, connection reset by peer. After inspecting the tcp 
transmission between the putty client and openssh server it appears that 
the maximum MTU limit of 1362 of the VPN connection, causes the server to 
break the 1460 byte cipher string into two packets. At that point the ssh 
client, putty or openssh, resets the connection. 

This was not a problem with openssh 6.1p1 since the cipher string was only 
1106 bytes and therefore transmitted in one packet. Since I am stuck with 
the VPN MTU limit of 1362, I am hoping that you could help in some form to 
get the ssh connection working again by, e.g., limit the cipher string to 
less than 1322 bytes?


Thanks in advance for any help you can provide to fix this problem,

Ernst Kratschmer