Microsoft ISA and OCS bypass Firewall problem.

[bapatsubodh]

Hi,

We are in process of installing the microsoft ISA server and also office communicatior server (OCS ). In order to make these applications available on internet we have placed both the servers in the DMZ region. With corrsponding Static entry with Public IP address in the ASA. Now the main problem is that both of these servers have second ethernet card and need to be connected directly to the inside region. ( in short one card will have IP from DMZ region and other card will have IP from inside region of firewall ) is it not bypassing the firewall? As traffic from one interface card can go to other interface card within the server itself bypassing the firewall - DMZ-to-Inside?

Is it not a security threat ?

any experience please share.

Thanks in advance

Subodh

[andrew.prince]

That is correct - in that case you might as well just plug the servers directly onto the internet!!

You could deploy a 2 layer firewall:-

Internet

|

FW1

|

DMZ

|

FW2

|

Inside

or depending on the type of firewall you could have multiple interfaces/vlans on the same device eg:-

internet

|

FW1 - DMZ

|

SVR

|

FW1 - DMZ2

|

Inside

HTH<