One thing to keep in mind with access lists is that they go in sequential order. So let's look at access list 2.
[code:1]access-list 2 remark HTTP Access-class list
access-list 2 remark SDM_ACL Category=1
access-list 2 permit 10.10.10.0 0.0.0.255
access-list 2 deny any[/code:1]
The first two lines are remarks or "comments" to let whoever is administering the router to get an idea of what the purpose of the ACL.
As the packet it received by the router, before it is forwarded, it is processed by the access list(s). It starts from the top, and goes until it matches a line. So, if a packet with a destination or source IP address of 10.10.10.0/24 is received, it will be filtered by access list 2 until the line permit 10.10.10.0 0.0.0.255. At this point, you can see the match, so it no longer goes through the access list and is forwarded. If the packet is from 192.168.200.0/24, it would go to the next line, deny any. The deny any is the catch all, and prevents anything else from getting through. Because it reached this pointed, the packet will be dropped.
Generally, you'll want to explicitly permit what you want to get through, and deny any thing else. That's why the deny any line is at the bottom of access lists. Access lists can get very complex, especially the more complex your network is. You'll be sure to learn this more in your later classes.
-Jeremy-
