[R] Ryacas not working properly

[Gabor Grothendieck]

Thanks for the clarification.

On 11/19/06, Marc Schwartz <marc_schwartz at comcast.net> wrote:
> Gabor,
>
> >From what I can tell, telnet service is not actually required to run
> yacas.  This is what confused me for some time and what raised the
> spectre of the concerns that had I for yacas to be dependent on telnet,
> as opposed to say ssh.
>
> On FC6 (and I suspect many other distros), telnet (plus or minus
> kerberos support) is not enabled by default, given the known security
> issues.
>
> One can, from the:
>
>  System -> Administration -> Server Settings -> Services
>
> menu, select the "On Demand Services" tab and enable telnet there.  This
> way, telnet is not running by default, but only when actually needed.
>
> After trying various permutations of settings, suspecting SELinux and/or
> firewall issues, I came to the conclusion that enabling this is not
> required.
>
> By default, the telnet server listens to port 23, which was another red
> flag that I had, noting the error messages for port 9734.  I noted no
> problems from iptables (the Linux firewall rules), given that I do not
> have port 23 open for telnet service.
>
> When yacas is running, I see no indication that processes related to
> telnet are running, which should be the case, given that I have
> explicitly disabled telnet as root and SELinux enforces those settings
> based upon mandatory policies.
>
> Without digging deeper into the yacas engine, it may very well be that
> without the --server-enabled option, it does require a telnet server to
> be running as the means to pass the expressions for evaluation. However,
> with that option enabled, yacas has its own server and uses port 9734. I
> also noted no references to 'telnet' in the config.log, created during
> the build process.
>
> However, I could not get yacas working without the server related
> option, even with telnet enabled, SELinux in Permissive mode and the
> firewall disabled on my system.
>
> This interaction was a great source of confusion, so it would be
> worthwhile to query the yacas folks to get some clarification relative
> to the presumptive dependency on telnet, which may end up being OS
> specific.
>
> HTH,
>
> Marc
>
> On Sun, 2006-11-19 at 19:32 -0500, Gabor Grothendieck wrote:
> > I don't have a UNIX box but my reading of it is that it is
> > telling one how to enable telnet on the machine -- not
> > how to install a server -- and that once telnet is enabled
> > then the Ryacas package can make use of sockets
> > whereas without that such use of sockets is disabled.
> > Is that not right?
> >
> >
> > On 11/19/06, Paul Smith <phhs80 at gmail.com> wrote:
> > > On 11/19/06, Gabor Grothendieck <ggrothendieck at gmail.com> wrote:
> > > > Thanks, Marc.  I have placed a link to your post on the Ryacas home page.
> > > > Also, Ryacas 0.2-3 is now on Omegahat (as well as google groups).
> > >
> > > Apparently, the link
> > >
> > > "HowTo - Enable Telnet on Linux"
> > >
> > > at Ryacas site is misleading, as it suggests the installation of
> > > telnet-server and that is not necessary. See the discussion at
> > >
> > > http://groups-beta.google.com/group/comp.os.linux.networking/browse_thread/thread/2bb6a4c7a1167285/565dde88d7922659#565dde88d7922659
> > >
> > > Paul
>
> <snip>
>
>
>