Help: rsh without password - Networking

This is a discussion on Help: rsh without password - Networking ; Hello, I'm building a Linux clusters so the clusters need log in nodes each other. I use rsh as a communication. I use RHEL 3, user is root user. However, I use which command to find out where rsh is, ...

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Thread: Help: rsh without password

  1. Help: rsh without password

    Hello,

    I'm building a Linux clusters so the clusters need log in nodes each
    other. I use rsh as a communication. I use RHEL 3, user is root user.

    However, I use which command to find out where rsh is, it shows
    /usr/kerberos/bin/rsh
    And in /etc/xinit.d directory I can't find the rsh, rlogin, and rexec
    daemons.

    So my problem is how to enable rsh to log in nodes without password.

    Thank you very much~

    Regards,

    Amy Lee

  2. Re: Help: rsh without password

    On Thu, 27 Dec 2007 20:24:53 +0800, Amy Lee wrote:

    > I'm building a Linux clusters so the clusters need log in nodes each
    > other. I use rsh as a communication. I use RHEL 3, user is root user.


    Rethink that. OpenSSH using key-based authentication is the best way to
    do what you wish.

    > However, I use which command to find out where rsh is, it shows
    > /usr/kerberos/bin/rsh
    > And in /etc/xinit.d directory I can't find the rsh, rlogin, and rexec
    > daemons.


    Probably because they have been deprecated and thus omitted from your
    distro, and for very good reasons.

    > So my problem is how to enable rsh to log in nodes without password.


    Use ssh instead. Create RSA keys for yourself:

    $ ssh-keygen -t rsa

    Copy your ~/.ssh/id_rsa.pub to the
    remote_systems:/home/amy/.ssh/authorized_keys.

  3. Re: Help: rsh without password

    On Thu, 27 Dec 2007 14:04:47 +0000, Dave Uhring wrote:

    > On Thu, 27 Dec 2007 20:24:53 +0800, Amy Lee wrote:
    >
    >> I'm building a Linux clusters so the clusters need log in nodes each
    >> other. I use rsh as a communication. I use RHEL 3, user is root user.

    >
    > Rethink that. OpenSSH using key-based authentication is the best way to
    > do what you wish.
    >
    >> However, I use which command to find out where rsh is, it shows
    >> /usr/kerberos/bin/rsh
    >> And in /etc/xinit.d directory I can't find the rsh, rlogin, and rexec
    >> daemons.

    >
    > Probably because they have been deprecated and thus omitted from your
    > distro, and for very good reasons.
    >
    >> So my problem is how to enable rsh to log in nodes without password.

    >
    > Use ssh instead. Create RSA keys for yourself:
    >
    > $ ssh-keygen -t rsa
    >
    > Copy your ~/.ssh/id_rsa.pub to the
    > remote_systems:/home/amy/.ssh/authorized_keys.


    Thank you very much. So from your words I have to reinstall rsh?

    Amy


  4. Re: Help: rsh without password

    On Thu, 27 Dec 2007 22:30:45 +0800, Amy Lee wrote:

    > On Thu, 27 Dec 2007 14:04:47 +0000, Dave Uhring wrote:
    >
    >> On Thu, 27 Dec 2007 20:24:53 +0800, Amy Lee wrote:
    >>
    >>> I'm building a Linux clusters so the clusters need log in nodes each
    >>> other. I use rsh as a communication. I use RHEL 3, user is root user.

    >>
    >> Rethink that. OpenSSH using key-based authentication is the best way
    >> to do what you wish.
    >>
    >>> However, I use which command to find out where rsh is, it shows
    >>> /usr/kerberos/bin/rsh
    >>> And in /etc/xinit.d directory I can't find the rsh, rlogin, and rexec
    >>> daemons.

    >>
    >> Probably because they have been deprecated and thus omitted from your
    >> distro, and for very good reasons.
    >>
    >>> So my problem is how to enable rsh to log in nodes without password.

    >>
    >> Use ssh instead. Create RSA keys for yourself:
    >>
    >> $ ssh-keygen -t rsa
    >>
    >> Copy your ~/.ssh/id_rsa.pub to the
    >> remote_systems:/home/amy/.ssh/authorized_keys.

    >
    > Thank you very much. So from your words I have to reinstall rsh?
    >
    > Amy


    NO NO NO!!! You don't want to use rsh, it's obsolete. SSH is already
    installed on all of your systems, ssh does everything that rsh did and
    more. As Dave told you the way to make ssh operate seamlessly is to
    generate a puplic/private key pair by doing

    ssh-keygen -t rsa

    This will put your keys into the directory .ssh. You should then take
    your public key, which is in
    ~/.ssh/id_rsa.pub
    and copy it into
    ~/.ssh/authorized_keys

    The you should should copy the .ssh directory into you home directories
    on all of the machines in your cluster. You will probably have to enable
    ssh on your systems. The really easy way to do this is to install webmin,

    http://www.webmin.com

    Webmin is a browser based admin tool that works on just about every
    distro,. After you have downloaded and installed webmin you access it
    from your web browser by goign to http://machinename:10000. In webmin go
    to the servers/ssh server section and configure ssh anyway you want,
    webmin makes everything self explanatory. You will also want to use
    webmin for SAMBA and NFS and just about any other server you have to
    administer, it's much easier to use that any distro based config tools
    that I've seen.

    After you have set it up all you have to do to log into another machine is
    ssh machinename

    To execute a program on another machine you do

    ssh machinename program

    To copy from one machine you can do either scp or rsync, for example to
    copy the directory foo do

    rsync -r -t foo machinename:/home/me

    ----------------------------------------------------
    One more thing, you should never be running as root, that's dangerous and
    pointless. Running as root is a bad habit from the Windows world, in
    Linux the only reason to be running as root is to do an admin task. And
    even when doing an admin task you never log in as root, you either use
    Webmin, use a root shell, or do sudo on the command.


  5. Re: Help: rsh without password

    Amy Lee writes:

    > On Thu, 27 Dec 2007 14:04:47 +0000, Dave Uhring wrote:


    >>
    >> Probably because they have been deprecated and thus omitted from your
    >> distro, and for very good reasons.
    >>
    >>> So my problem is how to enable rsh to log in nodes without password.

    >>
    >> Use ssh instead. Create RSA keys for yourself:
    >>
    >> $ ssh-keygen -t rsa
    >>
    >> Copy your ~/.ssh/id_rsa.pub to the
    >> remote_systems:/home/amy/.ssh/authorized_keys.

    >
    > Thank you very much. So from your words I have to reinstall rsh?


    No, what he said is you shouldn't use rsh. ssh does everything rsh
    does, it does a whole lot more (things like tunnelling X if you need
    that), and it does it with much better security. Admittedly, it takes
    a little more CPU because of the encryption, but not enough to be
    significant.

  6. Re: Help: rsh without password

    On Thu, 27 Dec 2007 09:01:44 -0600, General Schvantzkopf rearranged some
    electrons to say:


    > -- One more thing, you
    > should never be running as root, that's dangerous and pointless.


    Ancient proverb:
    She who plays in root, kills tree.

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