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Cisco ASA Firewall settings

My environment has two separate domains, with a Cisco ASA 5520 acting as Firewall/router in between the 2 domains, and between them and the internet.

Domain A uses the "Inside" interface and has 3 domain controllers

Domain B uses the "Public" interface and has 2 domain controllers

I need to set up domain trust between the domain controllers in the 2 domains.

Right now, All domain controllers on domain A can ping all DC's on domain B.
NO domain controllers on domain B can ping any DC's on domain A.

What access rules do I need to configure on the ASA to allow DCB1 and DCB2 access to DCA1, DCA2 & DCA3, while blocking any other traffic from domain B to domain A?

I would appreciate some assistance, as right now all traffic from B to A is blocked and I cannot create the trust.
3 Solutions
Not an optimal setup from a networking standpoint.    The ASA uses 2 zones like this for security where inside is trusted and outside is not trusted.     In order to get device on the outside to speak with devices on the inside, you need to create a Static NAT from outside to inside, create an access-list to allow the traffic, and finally apply that ACL to an interface.  

Something like this:

static (inside, outside) netmask
static (inside, outside) netmask
static (inside, outside) netmask

access-list outside_in extended permit ip host
access-list outside_in extended permit ip host
access-list outside_in extended permit ip host

access-group outside_in in interface outside

Andrea_Author Commented:
Sorry, I left out some key information.  
Both of those interfaces are on the inside.
The ASA actually has 5 interfaces configured (1 outside, 4 inside):
*** Outside  (198.111.167.xxx)
Inside  (
Public  (
Publicwlan (
Management (

Am I correct that the rules would be different since these interfaces are both internal?
Andrea_Author Commented:
Can anyone help me?  I really need to get these domain controllers talking to each other!
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What are the security levels of the 2 interfaces?
1st, make them the same
2nd, check the box to allow same-security traffic inter-interface
3rd, create a network static
static (Inside,Public) netmask
4th, create an access-list
access-list Public-Inside permit ip
5th, apply the acl to the Public interface
access-group Public-Inside in interface Public
Andrea_Author Commented:
I want to make sure I understand your directions.  
Step 3, is that creating a static NAT?  or is there another type of static network I should be configuring?
Well, if security level is the same you would not need static NAT. Just make security levels the same and issue same-security traffic inter-interface - this will allow communication from one LAN to another.
Andrea_Author Commented:
Thanks to all of you for your help.  
My solution ended up being this:
In the ASDM console:
Configuration- Firewall- Public Servers-
inside ip public
inside ip public
inside ip public

That allowed my domain B servers to find my domain A servers, so that my access rules would work.
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