Firewall Wizards mailing list archives
RE: PIX 520 - control traffic between DMZ and inside devices
From: "Brian A Kee" <bkee () lurhq com>
Date: Wed, 18 Dec 2002 02:27:26 -0500
I am glad that I could help, and I am sorry that I could not help enough to fix the problem. Can you post an example of the rules you added. I have run into many problems similar to what you discussed with NAT on the PIX. The Nat 0 rules that I discussed seem to work, but I do not know if I really like the solution all that much. I would be interested in seeing how you accomplished this. Thanks BAK -----Original Message----- From: Eye Am [mailto:eyeam () optonline net] Sent: Tuesday, December 17, 2002 12:56 PM To: Brian A Kee Cc: firewall-wizards () honor icsalabs com Subject: Re: [fw-wiz] PIX 520 - control traffic between DMZ and inside devices Thanks Brian! We did use NAT, static xlate from DMZ to inside, and access-lists to limit port/machine access from DMZ to inside. Cisco finally helped me figure out why I was confused and why it wasn't working as desired. Interestingly they had me create static xlates very different than any of the "rules" state on any CCO documents I read. Normally a static statement xlates two different IP addies but they had me NAT the same IP address inside and DMZ. Never saw that done and haven't found anything on CCO discussing the practice. Also since our DMZ machines have a default gateway of the PIX and our inside machines have a default gateway of the MSM router, traffic would never flow between the two interfaces without configuration on the MSM. We set up Policy Based Routing on the MSM applying access-lists to the inside VLAN. Without this, even static routes assigned on the servers will not flow to the DMZ. This had something to do with the metric of static routes being overridden by that of the direct connected vlans. Thanks again for your help. ----- Original Message ----- From: "Brian A Kee" <bkee () lurhq com> To: "Eye Am" <eyeam () optonline net>; <firewall-wizards () honor icsalabs com> Sent: Tuesday, December 17, 2002 9:47 PM Subject: RE: [fw-wiz] PIX 520 - control traffic between DMZ and inside devices
Correction!! I thought about this a little more last night. The Nat 0 rule should be used for the internal server. nat (inside) 0 <Internal-ServerIP> <Mask> BAK -----Original Message----- From: firewall-wizards-admin () honor icsalabs com [mailto:firewall-wizards-admin () honor icsalabs com]On Behalf Of Brian A Kee Sent: Monday, December 16, 2002 6:53 AM To: Eye Am; firewall-wizards () honor icsalabs com Subject: RE: [fw-wiz] PIX 520 - control traffic between DMZ and inside devices Remember that with the PIX you must take account for the security level of the interface. If you are going from a lower security level to a higher level, you will need a NAT rule and an ACL (conduit). In this case you
could
probably use NAT 0(zero). This will allow trafic to traverse the PIX from the DMZ to the Inside. Keep in mind you will still need ACLs (conduits) to allow the specified traffic. Assuming you have the Server Statically mapped to an external Address: static (dmz,outside) <LocalIP> <GlobalIP> netmask <Mask> you should be able to configure a nat 0 (zero) rule like: nat (dmz) 0 <LocalIP> <Mask> The staqtic shouls translate all requests from the outside world, while
the
Nat 0 (zero) rule should grab all request originating from within the Internal Network. There should be several other ways to do this. BAK -----Original Message----- From: firewall-wizards-admin () honor icsalabs com [mailto:firewall-wizards-admin () honor icsalabs com]On Behalf Of Eye Am Sent: Monday, December 16, 2002 12:14 PM To: firewall-wizards () honor icsalabs com Subject: [fw-wiz] PIX 520 - control traffic between DMZ and inside devices Being confused right now, I'll try to word this as un-confusing as
possible.
Scenario as follows The pic at http://security.kicks-ass.org:911/DMZ_CONFIG.gif is the basic network configuration I need and will be needed to make any sense out of
the
following. PIX 520, Three interfaces - inside, Outside and DMZ. Webserver (Win2kServer) in DMZ. 6509 Switch with MSM (routing) Traffic successfully limited to ports 80 and 443 between Outside and DMZ
in
the PIX using NAT/Access-list/Group Default gateway for the all DMZ devices is the PIX int E2 "DMZ" Default gateway for all inside devices is my.PRV.net.14 "6509MSM" I can successfully ping any DMZ device from the 6509 MSM si it knows how
to
get to DMZ and back. I cannot ping any inside devices from the PIX "DMZ" interface I cannot ping any DMZ devices from any devices on the inside Hers's my quandry: The webserver also needs to be limited to port 1433,
TCP
and UDP, to a specific MSSQL server on the inside and all traffic may flow on all ports to another computer on the inside. How do I control traffic between DMZ and inside devices? Is this do-able within the PIX or do I need to use MSM (or combination) to complete this piece? I've been tearing my hair out trying to get this to happen in the PIX to
no
avail. Seems no matter what combination of access-lists/groups I install there is no limit to traffic flowing between DMZ and inside. TYVM Chuck Genrich _______________________________________________ firewall-wizards mailing list firewall-wizards () honor icsalabs com http://honor.icsalabs.com/mailman/listinfo/firewall-wizards _______________________________________________ firewall-wizards mailing list firewall-wizards () honor icsalabs com http://honor.icsalabs.com/mailman/listinfo/firewall-wizards
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Current thread:
- PIX 520 - control traffic between DMZ and inside devices Eye Am (Dec 16)
- RE: PIX 520 - control traffic between DMZ and inside devices Brian A Kee (Dec 16)
- RE: PIX 520 - control traffic between DMZ and inside devices Brian A Kee (Dec 17)
- Re: PIX 520 - control traffic between DMZ and inside devices Eye Am (Dec 17)
- RE: PIX 520 - control traffic between DMZ and inside devices Brian A Kee (Dec 17)
- Re: PIX 520 - control traffic between DMZ and inside devices Luca Berra (Dec 22)
- RE: PIX 520 - control traffic between DMZ and inside devices Brian A Kee (Dec 17)
- RE: PIX 520 - control traffic between DMZ and inside devices Brian A Kee (Dec 16)
- <Possible follow-ups>
- Re: PIX 520 - control traffic between DMZ and inside devices Miha Vitorovic (Dec 17)
- RE: PIX 520 - control traffic between DMZ and inside devices Eye Am (Dec 30)