Ok, so recently we updated some of our Linux systems, some we have not. When I tried to SSH into an older system from a newer system I received an error:
“Unable to negotiate with 192.168.1.3 port 22: no matching cipher found. Their offer: 3des-cbc” ?!
I’ve seen similar errors before, didn’t make good notes on how it was resolved.. so here are a couple of items.
1 – nano ~/.ssh/config and set the connection parameters for each server you often connect to using the example below: – there are other items you can provide but this is all I needed to login!
Host myserver Hostname my-linux-host.local User angeln Port 22 Ciphers 3des-cbc
There are other things you can do, like add ciphers to the server – but I don’t cover that here. If elect to try it, i’ll post some details here in the future. Google It!?
FYI – a new useful tool, you can use verbose mode to see the ciphers the client is trying and the server is responding too … ssh -vvv angeln@192.168.1.3
-v Verbose mode. Causes ssh to print debugging messages about its progress. This is helpful in debugging connection, authentication, and configuration problems. Multiple -v options increase the verbosity. The maximum is 3