Re: [Sheflug] rlogin

[Al Hudson <nospam [at] york.ac.uk>]

On Mon, 29 May 2000, Ian Wright wrote:

> Thanks for the comments Barrie but I'm not sure I need 'commercial' level
> security.

It's usually good to get into good habits, though ;)

> I looked at ssh but, after 5 attempts, I still haven't managed to do a
> successful ./configure on it!

What's not succeeding? It's probably that you don't have one of the
packages that it depends on.

> The thing which is puzzling me at the moment is that I can 'rlogin' from
> 'brass' (Mandrake 7) to 'steel' (RH5.2) but not vice versa and, when I am
> 'rlogin-ed' to 'steel' I still can't run programs on that box. The error
> message I get is
> 
> Xlib: connection to "steel.metals.com:0.0" refused by server
> Xlib: Client is not authorised to connect to server

You're trying to run X-programs. Before rlogin'ing in, type 'xhost
+steel'. Then it'll work, in fabulous ways Windows users can only dream of
;) Rlogining in from steel to brass is just a matter of configuring your
allow and deny files, as mentioned in previous posts.

> What puzzles me is that a) I haven't set either machine up as a 'server'

Yes you have. 'X-server'. It's not called a server for nothing - all the X
graphics go down the network I'm afraid ;)

> b) I have now opened up the security on both machines so that they would
> effectively allow full access to anyone from anywhere

X permissions are slightly different to the other files ;)) There are a
number of different files in different places, depending on where in the
TCP/IP stack you're trying to lock the machine out. X locks out at the
application layer; firewalling often takes place in the network or
transport layer. There's a lot of doors in the way ;)

> Can anyone tell me what is going on please and explain in Janet and John
> language how to run a program residing on one machine on another

Firstly, you have telnet going in only one direction (rlogin is
essentially the same as telnet ;). First get telnet going in both
directions - you may need to change any firewall settings you might have
to do this. Mandrake 7 by default puts a fairly secure setting in, so
you'll need to back a lot of that out. Also, don't try telnetting as root
- that's the first thing they don't let you do ;) Go into Linuxconf (or
whatever your favourite tool is) and have a look around; especially in the
firewall section - it could be that port 23 (telnet) is being blocked. 

Next, realise that you're trying to run graphical programs over the
network - you need to configure X properly to do this. The xhost command I
mentioned above will do this. You can place this in a start-up script if
you like, to save you typing it in.

> RH5.2 but I have Ktimemon and ptimetracker on the Mandrake box. I had
> thought that this linux across networks was supposed to be the bees knees
> but I'm beginning to think its more like the wasps backside...

Once you understand, you'll see that it is the one true way. Almost ;)) It
just takes a little practice!

Cheers,

Alex.

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