Firewall Wizards mailing list archives
Re: PIX question
From: "Avishai Wool" <avishai.wool () gmail com>
Date: Tue, 14 Mar 2006 00:46:06 +0200
On 3/10/06, Brian Loe <knobdy () gmail com> wrote:
So, you have an internet-out ACL which ends with an any any on the inside interface. You have an internet-in ACL on the outside interface. You have a DMZ2-in ACL on the dmz2 interface. The inside interface is 100, dmz2 is 10 (as is dmz1) and the outside interface is 0. You have an smtp box on dmz2. You have rules in dmz2-in allowing the smtp box to talk to boxes on the internal network. The smtp box can NOT talk to anything on the internet - gets denied by dmz2-in ACL. Add an any any rule for that host in dmz2-in and it works. Question: Why would the inbound ACL on dmz2 prevent it from sending traffic to the outside interface with a lower security setting? Does an ACL applied to a dmz interface have an implied deny all - even for lower security interfaces?
yes it does. Once you put an ACL on an interface then you create a (sensible) default "deny all" on that interface - regardless of security levels. the (unfortunate) default "permit" from high-to-low only happens if you have no ACLs on the interface or if you're still using the (old, brain-dead) "conduit" and "outbound" commands. the security level still matters for your choice of address translation commands: "static" for low-to-high traffic, and "global"+"nat" for high-to-low traffic. HTH, Avishai
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Current thread:
- PIX question Brian Loe (Mar 13)
- RE: PIX question Bruce Smith (Mar 14)
- Re: PIX question Avishai Wool (Mar 14)
- Re: PIX question david_harris (Mar 15)
- <Possible follow-ups>
- RE: PIX question Martijn Berlage (Mar 14)