# PuTTy and 10.3



## banded (Jun 20, 2016)

Hi,

I just created a new 10.3 64-bit VM.  Unlike my 10.1 VMs, I was unable to use PuTTy to SSH into the machine.

Whenever I try to connect, I get this error message on the server:

```
error: Received disconnect from 192.168.0.100 port 52277:2: Server protocol violation: unexpected SSH2_MSG_UNIMPLEMENTED packet [preauth]
```
PuTTy reports:

```
Disconnected: Server protocol violation: unexpected SSH2_MSG_UNIMPLEMENTED packet
```
Any ideas of what's going on?  I really have no idea what to do with this.  In the past, I've been able to install FreeBSD and start using PuTTy, right away.


----------



## Murph (Jun 20, 2016)

10.3 updated OpenSSH to version 7.2 (latest stable).  Amongst other things, this added the Ed25519 key type, ChaCha20 cipher, and possibly some new MAC types as well.  This is just a guess, but it could be that older versions of PuTTY choke on the offer of the new options.

Make sure you are using the latest version of PuTTY.  Also, if you have previously customised /etc/ssh/sshd_config, you should probably review it to ensure that the config is suitable for 7.2.


----------



## banded (Jun 20, 2016)

Thanks. It appears that something was incompatible with the older version of PuTTy that I was using. I've upgraded, now and things are working!


----------



## drhowarddrfine (Jun 20, 2016)

I always thought putty was only for goofy Windows. Never knew it was available here. Not that I have a use for it but who said you can't learn anything new?


----------

