It never ceases to amaze me that an IT department head can make decisions without having a shred of relevant data pertaining to their network. How much bandwidth do we use on our Internet link? How about our (Frame-relay|PTP|MAN|WAN)? How much data do our servers push? Are there a few internal hosts hogging the pipes? Do we need more? Not having accurate historical data is like not having a memory; you can't kno It never ceases to amaze me that an IT department head can make decisions without having a shred of relevant data pertaining to their network. How much bandwidth do we use on our Internet link? How about our (Frame-relay|PTP|MAN|WAN)? How much data do our servers push? Are there a few internal hosts hogging the pipes? Do we need more?Not having accurate historical data is like not having a memory; you can’t know anything about your present situation without knowing the past. There’s no better way to wrangle for money to increase bandwidth than to provide a chart of a years’ worth of bandwidth utilization clearly showing a trend of growth. You don’t even need to be technical to understand that. IT Guy: We need to increase our Internet bandwidth. Finance Guy: Our what? IT Guy: The circuit that connects us to the Internet. Finance Guy: An electrical circuit? IT Guy: Kinda. This one transmits data though, not power. You use this to get to www.hamsterdance.com Finance Guy: Oh. I love that one. How much? IT Guy: One thousand dollars a month should do it. Finance Guy: What? IT Guy: One thousand dollars. Finance Guy: What? IT Guy: Here. This chart shows what we were using last year to this year. See? We’re using 100% more than this time last year. See? Look at the colors. Finance Guy: Oh. Okay then.Note: Your results may varyThis isn’t just about bandwidth, either. Graphs of server/SAN disk, server CPU, memory, and paging utilization over time is a very, very valuable tool. Unfortunately, it’s not possible to simply install and immediately reap the rewards; you need it running a year ago to find it usable now. Everyone should know and love MRTG. Get to know RRDTool while you’re at it. If you use SpamAssassin, Try GraphDefang. Good stuff.