Great Circle Associates Firewalls
(December 1995)
 

Indexed By Date: [Previous] [Next] Indexed By Thread: [Previous] [Next]

Subject: Re: modems and accessing the internal network
From: "Chris Liljenstolpe (Swanson) - SSDS" <Chris . Liljenstolpe @ SSDS . com>
Date: Tue, 12 Dec 1995 22:00:59 -0600
To: cbriese @ ripken . bmc . com (Chuck Briese)
Cc: H Morrow Long <long-morrow @ CS . YALE . EDU>, cbriese @ ripken . bmc . com, frankw @ in . net, firewallS @ GreatCircle . COM

Greetings,

        I disagree, if you are using certain types of software as your
security rule-set enforcer (normally called a firewall), you should be able
to say:

1) from the untrusted-internet - don't allow anything other than mail
(proxied) and DNS (proxied) etc.
2) from the untrusted-dialup - Allow full access after authentication.

        Regards,
        -+Chris

P.S.  This keeps it to one system instead of two - decreasing the number of
systems that must be monitored and hardened.

        Regards,
        -+Chris

At 15:22 95/12/11 -0600, the sage, Chuck Briese, uttered these words:
(>On Dec 11, 15:10, H Morrow Long wrote:
(>> Subject: Re: modems and accessing the internal network
(>>
(>> Why not set up yet a third classification of network in addition to the
(>> first two ( inside-corporate-trusted, outside-internet-untrusted )
(>> which is :    "dialup-untrusted"
(>>
(>> You could then have the dialup network exist separate from the DMZ and
(>> (Scenario 1) either share the same filtering router or proxy firewall
(>> setup or (Scenario 2) have a completely different firewall between the
(>> dialup-untrusted bank and the inside-corporate-trusted LAN.
(>>-- End of excerpt from H Morrow Long
(>
(>I am an advocate of Scenario 2 because the firewall needs of the
(>dialup/ISDN user are different from the firewall protecting the
(>internal network from the DMZ. I can simply specify "no telnet, no X,
(>no NFS, etc..." from the DMZ to the internal network.
(>
(>However, these users, particularly those with ISDN connections,
(>require NFS and X traffic to be passed to machines at their
(>homes/offices. While I might be able to place a firewall between
(>the remote and internal networks, how effective would it really be?
(>
(>I ran across this example of what I fear in the appsrvr man page from
(>my Pipeline software:
(>
(>HISTORY
(>    This command is only here because some system admins think its a great
(>    way to prevent folks from actually wanting to work via an ISDN link.
(>--
(>Chuck Briese, striving for zero defects in an inherently defective world
(>BMC Software, Inc., 2101 City West Blvd., Houston 77042  (713) 918-1216
(>
(>
--
    ( (   | (               Chris Liljenstolpe <Chris .
 Liljenstolpe @
 ssds .
 com>
     ) ) (|  ), inc.        SSDS, Inc; 8400 Normandale Lake Blvd.; Suite 993
    business driven         Bloomington, MN  55437; 
  technology solutions      TEL 612.921.2392  FAX 612.921.2395   Um Yah Yah!


Indexed By Date Previous: Internal Web server access
From: "Chris Liljenstolpe (Swanson) - SSDS" <Chris . Liljenstolpe @ SSDS . com>
Next: Re: connections from localhost 127.0.0.1
From: newton @ communica . com . au (Mark Newton)
Indexed By Thread Previous: Re: modems and accessing the internal network
From: "Paul D. Robertson" <proberts @ clark . net>
Next: Re: modems and accessing the internal network
From: "Dwight Doty" <doty @ navier . ctas . com>

Google
 
Search Internet Search www.greatcircle.com