vnstat-daily network statistics from the CLI

I found vnstat a few days ago, when I was researching netflow monitors for Cacti. Cacti is great for providing a visual display of almost anything that you can query through SNMP, which, provided the extendability of SNMP, can be numeric output from any script over time.

Sometimes, it's nice to have a CLI tool though, that can provide both an active and a historical view of traffic on an interface.It would also be an added benefit, if you didn't _have_ to be root, and more importantly didn't need to sniff the network interface(which is usually quite CPU/memory intensive) vnstat fills this requirement very nicely, and it is an (k)ubuntu package, so just apt-get install it.

After you install it, you need to run
vnstat -u -i eth0 (or eth1, or whatever interface you want to monitor)

It's possible to monitor multiple interfaces

then wait a while for it to gather some data(it reads /proc btw), and then you can have it report by hour(-h) by day(-d) by month(-m) or top10(-t):
Example: vnstat -u -i ath0

ath0 22:56
^ r
| r
| r
| r
| r
| r
| r
| rt
| rt
| rt
-+--------------------------------------------------------------------------->
| 23 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22

h rx (kB) tx (kB) h rx (kB) tx (kB) h rx (kB) tx (kB)
23 0 0 07 0 0 15 0 0
00 0 0 08 0 0 16 0 0
01 0 0 09 0 0 17 0 0
02 0 0 10 0 0 18 0 0
03 0 0 11 0 0 19 0 0
04 0 0 12 0 0 20 0 0
05 0 0 13 0 0 21 0 0
06 0 0 14 0 0 22 3 1