Ssh (Secure Shell) FAQ - Frequently asked questions
                                       
by Thomas König Thomas.Koenig@ciw.uni-karlsruhe.de

   $Date: 1997/06/06 20:14:08 $
   
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   This document is a list of Frequently Asked Questions (plus hopefully
   correct answers) about the Secure Shell, ssh.
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1. Meta-questions

     * 1.1 Where do I get this document?
     * 1.2 Where do I send questions, corrections etc. about this
       document?
       
2. Ssh basics

     * 2.1 What is ssh?
     * 2.2 Why should I use it?
     * 2.3 What kinds of attacks does ssh protect against?
     * 2.4 What kind of attacks does ssh not protect against?
     * 2.5 How does it work?
       
3. Obtaining and installing ssh

     * 3.1 What is the latest version of ssh?
     * 3.2 May I legally run ssh?
     * 3.3 What about commercial use of ssh?
     * 3.4 Where can I obtain ssh?
     * 3.5 How do I install it?
     * 3.6 Does it make sense to install ssh as non-root under UNIX?
     * 3.7 Where do I get help?
     * 3.8 Are there any versions for other operating systems than UNIX?
     * 3.9 What about administration of ssh?
       
4. Ssh Applications

     * 4.1 Can I run backups over ssh?
     * 4.2 Should I turn encryption off, for performance reasons?
     * 4.3 Can I use ssh to communicate across a firewall?
     * 4.4 Can I use rdist with ssh?
     * 4.5 Can I use ssh to securely connect two subnets across the
       Internet?
     * 4.6 Can I use ssh to securely forward UDP-based services, such as
       NFS or NIS?
     * 4.7 Can I forward SGI GL connections over ssh?
     * 4.8 Can I use ssh to protect services like ftp or POP?
     * 4.9 Can I use ssh across a Socks firewall?
     * 4.10 Is there ssh support for AFS/Kerberos?
       
5. Problems

     * 5.1 ssh otherhost xclient & does not work!
     * 5.2 Ssh fails with "Resource temporarily unavailable" for Solaris
     * 5.3 Sshd hangs under Solaris 2.5!
     * 5.4 X11 forwarding does not work for an SCO binary with the iBCS2
       emulator under Linux.
     * 5.5 Ssh is doing wrong things for multi-homed hosts!
     * 5.6 Userid swapping is broken under AIX!
     * 5.7 ssh-keygen dumps core on Alpha OSF!
     * 5.8 ssh-keygen dumps core on Solaris or SunOS
     * 5.9 On Linux, compilation aborts with some error message about
       libc.so.4
     * 5.10 X authorization sometimes fails.
     * 5.11 Ssh asks me for passwords despite .rhosts!
     * 5.12 Why does ssh loop with "Secure connection refused'?
     * 5.13 ssh-agent does not work with rxvt!
     * 5.14 X authorization always fails.
     * 5.15 ssh hangs when forwarding multiple TCP connections.
     * 5.16 What does Warning: remote host denied X11 forwarding mean?
     * 5.17 I still see cleartext packages on the net when I run ssh!
     * 5.18 I have problems with RSAREF, something to do with too many
       bits!
     * 5.19 Compiling fails with some error messages from the assembler.
     * 5.20 Compiling with Solaris 2.5 fails!
     * 5.21 Ssh suddenly drops connections!
     * 5.22 Connections are forwarded as root by ssh!
       
6. Miscellaneous

     * 6.1 What known security bugs exist in which versions of ssh?
     * 6.2 How widespread is use of ssh?
     * 6.3 I don't like the commercial aspects of ssh.
     * 6.4 Credits