[comp.protocols.tcp-ip] Unauthorized access via terminal servers

CALIFFM@BAYLOR.BITNET (Michael Califf) (12/21/89)

Barry -

We (Baylor University) have been wrestling with this same
problem.  We are currently solving it by piping all of our
modem-to-network connections through our data PBX.  The PBX
allows us to restrict connections from dial-in modems by
enforcing a username/password/access list check on an
attached machine as part of the logon.  The network-to-
modem connections are also piped through the PBX.

We use the terminal server's security software to restrict
the IP addresses allowed to make a connection into the server
(we have to worry about people making long-distance calls
as well, to make sure auth-codes don't get "borrowed".)

Mike Califf                    (POSTMAST[ER])
Communications Software Coord  Internet: CALIFFM@BAYLOR.EDU
Baylor University C.C.I.S.     Bitnet:   CALIFFM@BAYLOR
B.U. Box 7268                  THEnet:   BAYLOR::CALIFFM
Waco, TX 76798-7268            Phone:    (817) 755-2711

brian@ucsd.Edu (Brian Kantor) (12/22/89)

What we did here at UCSD to solve the problem of unauthorized network access
from our dial-up Annex boxes is to hack up the nice Annex security code.

Now if you dial up one of our boxes, you can telnet (or rlogin) to
machines on a list of networks (our three class-B nets and the UC
systemwide library catalog Class-A network) without user verification,
but if you want to connect anywhere else, we'll demand of you for a userid
and a password, which are checked against a database.

Thus students, staff, and faculty have no impediments in getting to the
various machines on our network and I don't have to be responsible for
maintaining access userids and passwords for some 20,000 people!

Those few people who need off-campus access can get it by registering
with us, and when someone abuses the access, I can turn it off.  Perhaps
not the best solution, but quite workable in our view.

	Brian Kantor	UCSD Network Operations
			UCSD C-024, La Jolla, CA 92093-0124 USA
			brian@ucsd.edu ucsd!brian BRIAN@UCSD