blocking telnet to selected IPs?

[Vladislav S. Davidzon]

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
> 
> 
>