ONT -- Network Audit...

snickered

I am in the first stage of implementing QoS. The Cisco Certification Guide says I need to do a network audit. I am well aware of squid, proxies, IPS(type) devices, etc... that are able to perform what I need. Does anyone have any suggestions of things they have implemented on the router within IOS that is helpful to get a good idea of traffic trends? That would certainly be the easy way out for me

cowood2676

Not exactly sure what you are asking but I think NBAR would do the trick for you.
NBAR is network based application recognition. It is just an app that looks at the packets to give you info as to what type of traffic is flowing through the network. Now if you use the ip nbar discovery commands, your device will start to report on what type of traffic if flowing but that is all. If you use auto discovery commands it uses NBAR and gets the same info & it prepares autoqos templates based off of the info NBAR collects so if you apply the auto qos command it applies what ever auto discovery comes up with. It is only available on Routers...not any MLS devices. Cisco reccomends that you run it for a minimum of 3 days. A word of warning would be to not enable it during peak traffic, when it starts you will take a pretty big hit on the routers CPU. It is the only app that will give you a true picture of what your router sees,

snickered

Good answer. I've heard of NBAR but haven't gotten as far as it telling me it can help with reconnaissance. Thanks!

Forsaken_GA

NBAR is good for figuring out what protocols are actually traversing your links.

If you're implementing QoS in a production environment, it's a good idea to get some data on the actual utilization of your links, so you can tell which links may be hurting, and which links may be undersubscribed. mrtg is a quick and dirty way to do that, though I personally use cacti (both of these are open source programs, if you're not familiar with them)