Cisco CCNA (640-553) Security Training
Using the “access-list compiled” command
By Charles Ross CCNA - CCNP #CSCO10444244
In today’s article, I’m going to quickly inform you about the Cisco IOS Global configuration command named “access-list compiled”.
Network administrators (like you) use the “access-list compiled” command to enable the Turbo Access Control Lists (Turbo ACL) feature.
In other words, CCNA’s use this command to turn on the Turbo ACL feature on a router.
The Turbo ACL feature, gives a router the ability to perform ACL acceleration processing; instead of normal ACL processing. Meaning, the router is able to scan thru the ACLs looking for the proper one (ACL); instead of sequentially searching for the proper one (ACL). And, once an ACL is found it is compiled for Turbo ACL acceleration processing.
Note: In certain situations, this scanning and compilation may take a few seconds when the router is processing large and complex ACLs, or when the router is processing a configuration that contains a large number of ACLs.
Also, if you decide to make a change to an ACL while it’s being accelerated, that ACL will automatically be recompiled.
And, when Turbo ACL tables are being built (or rebuilt) for a particular ACL, the normal sequential ACL search is used until the new tables are ready for installation.
Below is the command’s syntax:
access-list compiled
As you can see, the command is very simply to implement; it doesn’t use any keywords or arguments.
Below is an example of the command being used:
Router>enable
Router#configure terminal
Router(config)#access-list compiled
Router(config)#exit
Router#copy run start
In the example above, the Turbo ACL feature is being enabled on the router.
And, like with mostly all Cisco IOS commands; you can use the word “no” in front of the command to remove (disable) the configured command; like you see below:
Router(config)#no access-list compiled
By the way, if you decide to use the command, make sure your router(s) is running Cisco IOS 12.1(1)E or higher.
I hope this article was very informative and helped you quickly understand the usage of the access-list compiled command. If you need to learn more; I suggest you visit my website, (www.ittechtips.com) were you’ll find the latest information regarding the Cisco CCNA (640-553) Security exam techniques.
To your success,
Charles Ross
CCNA- CCNP #CSCO10444244