openssh from RHAT 7.0 doesn't work with the server/client from ssh.com. When trying to connect from 7.0 to a machine with the ssh.com sshd2 running (tried that server on Irix and RHAT 7.0), you get the following error: Disconnecting: Corrupted HMAC on input. Connecting from a ssh.com ssh2 client gives a similar error: Disconnected; MAC error (Message authentication check fails.). Same works fine with a 2.2.0p1-2 RPM package on Red Hat 6.2.
*** This bug has been marked as a duplicate of 17835 ***