Technical data

4. Packages
If you created a new host key set SSHD_CREATEHOSTKEYS back to ’no’ to avoid creating
another host key on every reboot.
If you log in to your fli4l router after updating the host key a warning message (depending
on the ssh client you use) will appear to inform you about the changed host key. In this
case this is normal because you just changed your host key. Follow the routine necessary
for your ssh client to accept the changed host key permanently. If some time in the future
you see this warning again you will have to check why it appears. Don’t just accept a
changed host key blindly!
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
ca:a4:ab:e7:af:d8:68:05:d3:1f:e6:15:08:d6:ed:36.
Please contact your system administrator.
Add correct host key in /home/babel/.ssh/known_hosts to get rid of this message.
Offending key in /home/babel/.ssh/known_hosts:7
Password authentication is disabled to avoid man-in-the-middle attacks.
SSHD_PORT Default setting: SSHD_PORT=’22’
By SSHD_PORT a non-standard port can be defined the ssh server should listen to.
If ssh login from outside should be allowed INPUT_ACCEPT_PORT_x (Page 42) has to be
adapted to reflect the change.
The commands accessing fli4l from an Unix-/Linux client over protocol SSH are:
• ssh - Secure Shell
• scp - Secure Copy
Corresponding programs are available for Windows as well, see:
http://www.chiark.greenend.org.uk/~sgtatham/putty/
http://winscp.net/eng/docs/lang:en
http://www.tectia.com/de/de.iw3
SSHD_PUBLIC_KEY_N Default setting: SSHD_PUBLIC_KEY_N=’0’
SSHD_PUBLIC_KEY_N holds the number of public keys to be copied to the fli4l router.
SSH allows authentification based on asymmetric encryption. Authentification is done via
username and public/private key instead of username and password. This way entering a
password can be omitted. Generate your key pair by the help of ssh-keygen (or puttygen if
putty under Windows is used as the ssh client). When generating keys you can optionally
specify a passphrase (a password for using the key) to increase security even more. If
using a passphrase you may consider working with an ssh agent (ssh-agent or pageant).
Important: The private part of the keypair has to be guarded as careful as a password
because it has the same function. The private part of your keypair is only known to your
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