I have a question in regards the ASA 5505. I totally understand the concept from higher to lower level, but I noticed something interesting while I was doing something at work today. Traffic from my inside could see my web server located in my DMZ via local IP address. For example source local IP (MyPC 192.168.1.50) was able to establish tcp session towards my Apache server addressed to 192.168.50.50. I thought once you've created level of security none of them interface should communicate unless you have an access-rule such as NAT or ACCESS-LIST in placed. Please let me know if im wrong.
Also, I have no routing nor access-list, just basic simple configuration, I just noticed it after mistakenly typed an IP address.