tailieunhanh - Better Security through Access-List Management

Security is becoming more and more common in every environment, regardless how big or small the network happens to be. Anytime we think of security, the first thing that comes to our minds is the implementation of firewalls. What if firewalls are not available in your network? What if your firewalls are only meant for connectivity from the outside world? Or, better yet, what if firewalls are controlled by different groups in your organization, and you want to do something to protect your network internally between departments and/or maybe your budget doesn’t allow you to get firewalls. Can you get somewhat similar. | Global Knowledge Expert Reference Series ofWhite Papers Better Security through Access-List Management 1-800-COURSES Better Security through Access-List Management Raj Tolani Global Knowledge Networking Instructor Introduction Security is becoming more and more common in every environment regardless how big or small the network happens to be. Anytime we think of security the first thing that comes to our minds is the implementation of firewalls. What if firewalls are not available in your network What if your firewalls are only meant for connectivity from the outside world Or better yet what if firewalls are controlled by different groups in your organization and you want to do something to protect your network internally between departments and or maybe your budget doesn t allow you to get firewalls. Can you get somewhat similar functionality with your existing routers The answer is yes. You can get limited security with the access-list on your routers. However access-lists on routers are in no way replacements for firewalls. The abilities of access-list have evolved a lot since they were introduced in the early versions of Cisco IOS. What you can and cannot do with access-list will vary between IOS releases. With the IOS Firewall Feature set you can do more than what will be discussed in this whitepaper. This paper gives you the basics of access-list with implementations examples as covered in the CCNA certifications. These CCNA focused access-lists are for TCP IP protocol only even though access-lists can control other protocols like IPX SPX and Appletalk. Typically when you think of access-list you think about permitting or denying certain type of traffic. You think of protecting your network from being hacked. Well that s not the only use for access-list. access-lists have many other purposes. For example with an access-list you can trigger your ISDN calls - to mark what interesting traffic will trigger the call. With access-lists you .