blocking telnet to selected IPs?

[Vladislav S. Davidzon]

I'm sorry, I was tired.  I take that back.  The program in question is
telnetd, the telnet daemon, not the mail daemon, sendmail.  Telnetd can be
filtered using TCP wrappers.

Regards,


Vladislav Davidzon
Technology Assistant, Farmington Community Library 
(248) 553-0300 (#333)
Unix/NT/Network Consultant & Web Designer

"The word impossible is not in my dictionary."
-Napoleon Bonaparte

On Sun, 12 Jul 1998, Vladislav S. Davidzon wrote:

> I am not sure if you can block sendmail via TCPWrappers, as sendmail
> usually runs as its own process, not via inetd.  I've never seen sendmail
> filtered out via tcpd [tcpwrappers], HOWEVER sendmail can be configured
> not to accept connections from certain hosts.
> 
> On Sun, 12 Jul 1998, Peter Murray wrote:
> 
> > --On Tue, Jul 7, 1998 12:34 PM -0700 "Dave Vose"
> > <dvose at library.lib.binghamton.edu> wrote: 
> > 
> > > We may be forced to discontinue email access in the library but we'd like
> > to
> > > retain telnet capability for access to other OPACs, etc. Is there a way 
> > > to block telnet access to selected IP addresses in Netscape 3.x and 
> > > 4.x?
> > 
> > If you have access to the machines providing the e-mail access and if they
> > are UNIX machines, you can install the TCP Wrappers package on the e-mail
> > machines to deny access from your OPAC stations.  Here is some info about
> > the TCP Wrappers package:
> > 
> >   With this package you can monitor and filter incoming requests for the
> >   SYSTAT, FINGER, FTP, TELNET, RLOGIN, RSH, EXEC, TFTP, TALK, and other
> >   network services.
> > 
> >   The package provides tiny daemon wrapper programs that can be installed
> >   without any changes to existing software or to existing configuration
> >   files.  The wrappers report the name of the client host and of the
> >   requested service; the wrappers do not exchange information with the
> >   client or server applications, and impose no overhead on the actual
> >   conversation between the client and server applications.
> > 
> > This package is maintained by Wietse Venema (wietse at wzv.win.tue.nl), and a
> > mirror in the USA can be found at: 
> > 
> >    ftp://coast.cs.purdue.edu/pub/tools/unix/tcp_wrappers/
> > 
> > 
> > Peter
> > --
> > Peter Murray, Library Systems Manager                    pem at po.cwru.edu
> > Digital Media Services                 http://www.cwru.edu/home/pem.html
> > Case Western Reserve University, Cleveland, Ohio          W:216-368-5888
> > 
> > 
> > 
> 
>