Many if not all network traffic capture utilities require that the network adapter has the promiscuous mode enabled.
To check if the promiscuous mode is on run:
Kernel Interface table
Iface MTU RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg
eth0 9001 9095 0 0 0 10367 0 0 0 BMRU
Look at the Flg column – if the P flag is missing the mode is not enabled.
To enable it run:
ifconfig eth0 promisc
ip link set eth0 promisc on
to get live memory usage just run:
watch -n 5 free -m
and one more:
that will print memory updates every 5 sek:
ifstat – InterFace STATistics Monitoring
ifstat is a tool to report network interfaces bandwith just like vmstat/iostat do for other system counters. It can monitor local interfaces by polling the kernel counters, or remote hosts interfaces using SNMP.
To install run:
apt-get install ifstat
then just issue:
KB/s in KB/s out
to be continued….
CPU and Running processes
I use the classic: top. Installed as standard in our distributions, It will display the processes running and sort them according to certain criteria.
Here for example that the command returns on my server :
By default, the command will sort the programs by their CPU usage. To change the sorting press: ‘ f’ to select fields to display, then you move with the arrows. The SPACEBAR to display a field then ‘ s’ to use the field as default sort.
To get some extra RAM reduce the graphics memory to 1MB using raspi-config tool:
Another great tool:
There is always webmin that will give you some additional info: