• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 640
  • Last Modified:

ASA 5510 - Question about ACL configuration

I have an ASA 5510 and would like to fine tune the ACL's on the device.

The interface and security levels are as follows

Outside / 0
Inside / 100
Production / 100

I have allowed same level security traffic flow on the device and want to restrict most traffic between the two internal networks.

For instance I currently have this statement on the inside interface.

access-list 102 line 18 extended permit tcp any any eq www

I just want that ACL to allow HTTP traffic to the outside interface (internet). However when I change the destination from ANY to the outside interface, or the outside network, web traffic is blocked.

Is this possible... or do I need to specify a deny statement  before that example ACL that would block HTTP traffic to the Production network.

Or to put the question differently. what is the proper way to configure the destination for external networks without using the any statement in the ACL




0
Highspade
Asked:
Highspade
1 Solution
 
MikeKaneCommented:
If I understood, you want the INSIDE network to have www access to the OUTSIDE but not to PRODUCTION.  

If that is correct, then you are right in your assumption.

Your acl should look something like this:

acl inside_access_out extended deny tcp <inside-subnet> <inside-subnet-netmask> <production-subnet> <production-subnet-netmask> eq www
acl inside_access_out extended permit tcp <inside-subnet> <inside-subnet-netmask> any eq www


The ACL's are read top to bottom and processing stops once there is a match.   So this acl would match the www request from inside to production and deny it, processing stops.   The next line allows for www to any address with the assumption that the production subnet would have been denied already if it matched.  

This could be simplified by:

acl inside_access_out extended deny ip <inside-subnet> <inside-subnet-netmask> <production-subnet> <production-subnet-netmask>
acl inside_access_out extended permit ip <inside-subnet> <inside-subnet-netmask> any

This one blocks all ip from inside to production, and then allows all ip everywhere else.  


This acl works if you use
access-group inside_access_out in interface inside





0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

Prepare for an Exciting Career in Cybersecurity

Help prevent cyber-threats and provide solutions to safeguard our global digital economy. Earn your MS in Cybersecurity. WGU’s MSCSIA degree program curriculum features two internationally recognized certifications from the EC-Council at no additional time or cost.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now