Introduction

I had the issue where we had upgraded a system and as a result when I tried to SSH to another system which had not been upgraded I recieved the following error:

Unable to negotiate with XX.XXX.XX.XX: no matching host key type found. Their offer: ssh-dss

Turns out this is because OpenSSH has deprecated DSA keys by default.

Solution

The easy solution to these is to adjust or create an ~/.ssh/config file with the following information:

Host your-remote-host
    HostkeyAlgorithms +ssh-dss

This will enable access to the system that previously wasn't allowed. Works for any SSH session including Rsync. http://stackoverflow.com/questions/34208495/unable-to-negotiate-with-xx-xxx-xx-xx-no-matching-host-key-type-found-their-of