What software can I use to provide the same features as SSH (openssh-server)? I have a busy server that I am losing all SSH connectivity once in a while. I can't find a solution to yet, we are investigating the possible causes but meanwhile we want to have a safe alternative, so we weren't locked out again (and have to reboot the server).
You can try other SSH servers such as lsh or Dropbear, which have less features and are not as thoroughly tested, but can be a good temporary alternative regardless.
There exists a Telnet server netkit-telnet-ssl which supports SSL/TLS encryption and authentication. However, even though TLS can provides sufficient security (provided the sysadmin is not lazy and obtains a SSL certificate), Telnet remains a generally poorly designed protocol for daily use.
The Telnet and rlogin servers from Heimdal and MIT krb5-appl Kerberos suites have support for Kerberos authentication and encryption; however, the crypto code in MIT telnetd is limited to DES64, and rlogin is from my experience even more of a pain in the ass to set up than Telnet.
Finally, check the system log, optionally after increasing LogLevel in
Since the sshd of Openssh has a
You'd have to set up the startup scripts appropriately (rc.local?) or run one out of (x)inetd?