[Beowulf] ssh connection passwordless

[Reuti]

Hi,

Am 19.03.2009 um 10:22 schrieb Francesco Pietra:

> I have a computing machine and a desktop ssh passwordless
> interconnected through a Zyxel router (which is dhpc on Internet). I
> have now added a second computing machine. I am unable to get all
> three machines passwordless interconnected at the same time. Just only
> two. If I want to have the third computer passwordless connected to
> one of the other two, I have to exchange id_rsa.pub between the two
> again. Mistake or intrinsic feature of ssh?
>
> What I did:
>
> (1)generating  the keys with "ssh-keygen -t rsa"
>
> (2) getting "reserved" the machines on the router
>
> (3)scp id_rsa.pub to the "authorized_keys"

- you can have more than one line in the authorized keys file, hence  
put there the id_rsa.pub from all other nodes in addition.

- when you need this only for interactive work, you can have a local  
ss-agent running on your desktop and put in ~/.ssh/config and on both  
node a two lines:

Host *
     ForwardAgent yes"

good explanation you can find here: http://unixwiz.net/techtips/ssh- 
agent-forwarding.html

- another option might be to setup /etc/ssh/ssh_known_hosts on your  
two compurte nodes to include per line the short hostname, the FQDN,  
the TCP-IP address besides the other hosts ssh keys (not the user's  
one) as this would avoid any password or adding of the machines to  
you personal ~/.ssh/known_hosts file. This won't work with your  
workstation of course as it's TCP/IP address varies.

-- Reuti


> It is also mandatory that asking the "date" to the other computer
> (slogin ... date), the date is given without asking the password. That
> is an issue of a computational code that for its internal
> parallelization needs that (I have not investigated why).
>
> thanks
>
> francesco
> _______________________________________________
> Beowulf mailing list, Beowulf at beowulf.org
> To change your subscription (digest mode or unsubscribe) visit  
> http://www.beowulf.org/mailman/listinfo/beowulf