Remote login to Linux

[hw-tph]

You could set up SSH to allow X forwarding.
When you do this, your students can log in to the server using SSH in an xshell (xterm, Eterm, Konsole, whatever) and launch apps on the server and have them displayed on their workstations, as if they were running the application on their own computer. This should work well even if the student's computers run Linux off of the CD-ROM.

If several users are to be using the server at the same time running applications on it, you should of course be looking at a server with some muscle since the applications are run on the server and only displayed on the workstations.

hw

[A. Jorge Garcia]

What about a thin-client? In other words reduce the bandwidth by running on the remote server only those jobs that need to.

Regards,

[A. Jorge Garcia]

OK, I got knx-hdinstall done on one machine and created a user called mrg (that's me: Mr. G). Then I booted another PC on the LAN with the KNOPPIX CD. I could get rlogin and ssh to login in as mrg@primeCentauri (10.10.2.64 intranet). But I could not use anything but shell!

How do I use apps from the KNOPPIX PC attaching to files on the Remote Server PC? Do I have to knx-hdinstall every PC and use xdm server or kdm to login remotely just as if I were to login locally?

Regards,

[hw-tph]

What about a thin-client? In other words reduce the bandwidth by running on the remote server only those jobs that need to.

Yes, that's what I had in mind. Sorry if I wasn't clear enough on that.

On the server you need to edit the /etc/sshd_config file and set the "X11Forwarding" line to "yes" instead of "no". This way you can log in using SSH to the server, execute a program - say, xeyes - and have it displayed on the local screen. It will act exactly as if you had it installed locally. If you open up a graphical editor (vim, kedit, or something) and save files the files will be stored on the server.

If you want to let apps launched on your local computer use the server's disk for storage (saving work, etc) that would mean setting up a little more advanced setup (possibly involving NFS shares). I haven't done that so I can't help you with it - sorry.

But you could do it the quick and ugly way by simply running the application locally, and when done upload your files to the server using FTP. I imagine that's not a very attractive option though.

hw

[A. Jorge Garcia]

OK, so if I enable X11forwarding, I can login the the remote PC from my local PC with ssh and save files there. Can I then run an app like KATE and save files remotely? I'm confused, b/c you say I can then run an app like xeyes and its running remotely, but looks like it srunning locally, right? But then you say if I run a app that creates a file, I can't save it remotely?

BTW, ssh is just a secure shell version of rlogin, right?

OK, what about the quick and dirty ftp option? I tried ftp 10.10.2.64 and it seemed to connect. The I tried to login mrg and it asked for a password, I supplied it and everything seemed ok. But then if I tried to ls the remote home dir, I got a timeout. Also, if I try to put a file on the remote home dir from the local home dir or get a file from the remote home dir to the local home dir I also get a timeout as if I'm not connected via ftp.

What gives here? Do you have any ideas?

TIA,

[Stephen]

OK, so if I enable X11forwarding, I can login the the remote PC from my local PC with ssh and save files there.

Yes but you do not need X forwarding to copy files you would want to use scp (secure copy) for that, it uses ssh to copy files securely over the network and would have been installed along with ssh. The scp syntax is like your regular copy command except you put the user name at the IP you are copying too e.g. scp file.txt user@123.456.789.012:/home/user/ would copy the file.txt to the home directory of the user.

Can I then run an app like KATE and save files remotely? I'm confused, b/c you say I can then run an app like xeyes and its running remotely, but looks like it srunning locally, right? But then you say if I run a app that creates a file, I can't save it remotely?

You would be running the application on the server with it being displayed over the network any files being created would be on the server.

OK, what about the quick and dirty ftp option? I tried ftp 10.10.2.64 and it seemed to connect. The I tried to login mrg and it asked for a password, I supplied it and everything seemed ok. But then if I tried to ls the remote home dir, I got a timeout. Also, if I try to put a file on the remote home dir from the local home dir or get a file from the remote home dir to the local home dir I also get a timeout as if I'm not connected via ftp.

What gives here? Do you have any ideas?

TIA,

Open Konqueror and in the address bar fish://mgr@10.10.2.64 and that will pop up a password dialog enter the password and then you have access to your machine.

A couple of links:
public key authentication
VNC article

[A. Jorge Garcia]

Stephen, as always, you are a god! This sounds just like what I need!!

OK, let me get this straight:
I don't need X11forwarding to use scp or fish, right?
I have to use ssh before I can use scp, right?
I don't need to use ssh to use fish right?

Also, what benefit would I get from using X11forwarding, then. I'm a bit fuzzy here....

TIA,

[Stephen]

Stephen, as always, you are a god! This sounds just like what I need!!

OK, let me get this straight:
I don't need X11forwarding to use scp or fish, right?
I have to use ssh before I can use scp, right?
I don't need to use ssh to use fish right?

Also, what benefit would I get from using X11forwarding, then. I'm a bit fuzzy here....

TIA,

You do not need the forewarding for ssh to work it is just text based so works from the command line no problem. With scp it is a seperate command that just uses ssh when you transfer the files over the network there is no need to use ssh first when you scp somefile user@123.456.789.012.:/desitination/directory it will ask you for the user's password while using ssh to encrypt the connection. For the fish it is the same as scp except you get to do it graphically it pops up a dialog to enter the password while using ssh for the connection and for what you are thinking of doing is probably perfect for the job you would just need accounts for each user on the server and they would have their own /home to save the files too.

The benefit of the X forewarding over ssh is security for running an application and having the results displayed over the network without it anyone could sniff the packets on the network and get the un-encrypted transmission.

[A. Jorge Garcia]

This is perfect! I'm going to show my students how to do this tomorrow (after I add some more users to the server of course).

OK, so we still work locally off the KNOPPIX CD (well, its really the "Poor Man's Dual Boot" using the huge KNOPPIX file from the CD - works the same), but when it comes time to save a file, they go
scp file1.java nancy@10.10.2.64:/home/nancy
or retrieve a file, they go:
scp nancy@10.10.2.64:/home/nancy/file2.java .

This will not be too different from what we do now. Now we use the "FastDOSBoot floopy" to boot the "Poor Man's Dual Install." There's plenty of room left on that floppy to save files. So when they save a file, they go:
cp file1.java /mnt/floppy
and to retrieve a file, they go:
cp /mnt/floppy/file2.java .

The only difference is instead of
ls /mnt/floppy
now they'll have to
shh -l nancy 10.10.2.64
first and then ls from the remote shell, right?

In any event, I won't need shh for anything else and I really can live without fish. Or am I missing something nice about fish? Well I guess "Konqueror fish://nancy@10.10.2.64" can replace ls without shh.

Now, I won't need a floppy for saving anymore!

I'm tempted to knx-hdinstall all the PCs with lilo in the mbr so we don't need boot floppies either - no floppies, no CDs, so much happiness! There's two problems with that. Whenever I do an hdinstall, I can't get printers to work with Kapps (KATE, KWrite, etc). Also, I've not had good experiences playing with the mbr....

Oh, thanx for the VNC link, I may just want to use it instead on a blackboard! I had a projection device attached to my PC in the back of the room so the kids could see me coding "real-time" last year in another lab. I really miss that! Maybe I can do something similar with VNC.

Thanx!

[Stephen]

This is perfect! I'm going to show my students how to do this tomorrow (after I add some more users to the server of course).

OK, so we still work locally off the KNOPPIX CD (well, its really the "Poor Man's Dual Boot" using the huge KNOPPIX file from the CD - works the same), but when it comes time to save a file, they go
scp file1.java nancy@10.10.2.64:/home/nancy
or retrieve a file, they go:
scp nancy@10.10.2.64:/home/nancy/file2.java .

Yes you got the idea right it's just the same as copy except it uses ssh.

This will not be too different from what we do now. Now we use the "FastDOSBoot floopy" to boot the "Poor Man's Dual Install." There's plenty of room left on that floppy to save files. So when they save a file, they go:
cp file1.java /mnt/floppy
and to retrieve a file, they go:
cp /mnt/floppy/file2.java .

The only difference is instead of
ls /mnt/floppy
now they'll have to
shh -l nancy 10.10.2.64
first and then ls from the remote shell, right?

Exactly.

In any event, I won't need shh for anything else and I really can live without fish. Or am I missing something nice about fish? Well I guess "Konqueror nancy@10.10.2.64" can replace ls without shh.

Yes if you were to login as fish://nancy@10.10.2.64 it would take user Nancy to her /home/nancy directory in effect a ls over ssh. I look at fish as just an easy way to get drag and drop scp if you split the window where your files are before you login in the other window. It sounds like the students are already used to the command line so start them with ssh and scp that way they know how to do it properly without GUI then if you want to give them a break and make it real easy for them show them fish.

Now, I won't need a floppy for saving anymore!

I'm tempted to knx-hdinstall all the PCs with lilo in the mbr so we don't need boot floppies either - no floppies, no CDs, so much happiness! There's two problems with that. Whenever I do an hdinstall, I can't get printers to work with Kapps (KATE, KWrite, etc). Also, I've not had good experiences playing with the mbr....

You could just install lilo to the / of the install instead of the MBR and use the XP bootloader to chainload the partition and let lilo take over from there at least I assume that XP will do that, will it? If you get no option to install to the / decline the offer to install to the MBR make the boot floppy then while still running from the CD sudo chroot /mnt/hd?? /sbin/lilo -b /dev/hd?? replace the ?? with the drive letter and partition number of the /. So you are still getting the same problems with the newer releases, I think all out of ideas from the last time around except if you have internet access on the machine(s) wipe out the entire CUPS install and start over from scratch re-install and get the drivers from http://www.linuxprinting.org for the printers go through the setup and see if it works as it should.

Oh, thanx for the VNC link, I may just want to use it instead on a blackboard! I had a projection device attached to my PC in the back of the room so the kids could see me coding "real-time" last year in another lab. I really miss that! Maybe I can do something similar with VNC.

Thanx!

Your welcome I thought you could most likely use something like that. I was just thinking you might want to check out Bonzai linux it's a pretty easy way to get Debian (Woody) on the system you still have to choose a few modules during the install but most everything you need should already be in the kernel you end up with KDE 3.1.? and kernel 2.4.20 last time I used it (beginning of the summer) and it only takes up about 400-500mb once installed then just get the extra packages you would want get yourself a base image install and just clone it across your network to the other machines.