Layer 4 switches

Dilan77

Hi All

Some switches, apparently, are capable of Layer 4 functionality, and I'm not too sure what this means? Does this mean the ability to filter packets by port number/ application, as in an extended access-list?

Thanks

keenon

Dilan77 wrote:

Does this mean the ability to filter packets by port number/ application, as in an extended access-list?

Thanks

yes it does.. this would include the ablity to nat as well

Dilan77

Thanks, so does this mean L3 switches aren't capable of extended ACL's?

mikej412

"switching" usually implies hardware. Layer 3 switching is routing done at wire speed using those custom ASICs. Once you go to software to process that layer 4 information -- you are no longer "switching."

A layer 3 switch processing an extended ACL is no longer "in hardware" -- that's why its not a layer 4 switch.

Ah... but when you say "layer 4 functionality" that could mean a layer 3 switch processing layer 4 information in software.

Sounds like sales weasel talk.

darkuser

http://computer.howstuffworks.com/lan-switch15.htm


http://www.networkworld.com/details/725.html?def