Security Compliance

PuTTY error: Couldn't agree a client-to-server cipher

PuTTY gives a fatal error when connecting to the SEM via SSH. PuTTY Fatal Error: Couldn't agree a client-to-server cipher (available: aes256-ctr,ase192-ctr,ase128-ctr)

First published date

10/11/2018 6:17 PM

Last published date

1/5/2022 6:48 AM

Overview

This article describes an error when using PuTTY to open an SSH session to the SEM appliance. In this scenario, PuTTY returns a fatal error:

Couldn't agree a client-to-server cipher (available: aes256-ctr,ase192-ctr,ase128-ctr)

Product section

Security Event Manager

Cause

This error is caused by an issue with the previous versions of PuTTY.

Resolution

To resolve, upgrade to the latest version of PuTTY.

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