SSH does not accept legacy Diffie-Hellman kex algorithm after upgrading Red Hat Enterprise Linux to 7.4 or higher

Solution Verified - Updated -


  • Red Hat Enterprise Linux 7.3 or older ssh clients that are using the diffie-hellman-group-exchange-sha256 kex algorithm are rejected if the SSH server the client connects to is running Red Hat Enterprise Linux 7.4 or higher.


  • Red Hat Enterprise Linux 7.4 or higher
  • openssh-server-7.4p1-16.el7.x86_64 or higher

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