No matching cipher found:

[makintola-29926b65fe]

Hello everyone/@kbogart-81b6c89deee9,

I get this error on my switch log, I have couple of users logging in regularly.

64529: No matching cipher found: client aes128-gcm@openssh.com,chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr server aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc

One research showed client is using aes128-ctr while the server is aes128-cbc, and causing a mismatch.

Kindy help for possible solutions.

Regards.

[kbogart-81b6c89deee9]

This thread on Reddit might help shed some light on this problem:

ssh Unable to negotiate: "no matching cipher found", is rejecting cbc

In short, it looks like whatever users are utilizing OpenSSH to gain SSH access into your switch need to modify their /etc/ssh/sshd_config file. Most likely they’ll need to manually add AES128-CBC to their file.
Hope that helps!
Keith

[jackyjoy826-25fa109e]

@kbogart-81b6c89deee9

In short, it looks like whatever users are utilizing OpenSSH to gain SSH access into your switch need to modify their /etc/ssh/sshd_config file. Most likely they’ll need to manually add AES128-CBC to their file.
Hope that helps!
Keit

thanks for the awesome information.