console snmp monitor

centosboy · 06-11-2009, 03:17 AM

Greetings to all.
I am looking for an shell/console bandwidth monitor that can measure bandwidth stats on remote switch interfaces/ports using snmp. Strictly no graphing, just average interval stats in a console. I do not mind if it is an ncurses console but would just prefer a simple kind of perl or shell script. I did have a go at writing one, but the results are just not what i expected....
I would be most grateful if anyone that knows of one points me in the right direction.

Ygrex · 06-11-2009, 09:02 AM

if you want to know a bandwith and nothing more, IMHO snmp is an excessive tool for you; snmp uses ifconfig's statictics for its calculations; you can do the same work without snmp

for example, the following script will continuously out put the specified interface statistics:

Code:

#!/bin/sh

# output precision
PRECISION=3
INTERVAL=1

while (true); do

# read statistics
STAT="$(ifconfig $1 | sed -n 's/^.*bytes:\([0-9]\+\).*bytes:\([0-9]\+\).*$/\1 \2/p')"

# received
rx[0]=$(echo $STAT | awk '{print $1}')
# transferred
tx[0]=$(echo $STAT | awk '{print $2}')

# wait
sleep $INTERVAL

# read statistics
STAT="$(ifconfig $1 | sed -n 's/^.*bytes:\([0-9]\+\).*bytes:\([0-9]\+\).*$/\1 \2/p')"

# received
rx[1]=$(echo $STAT | awk '{print $1}')
# transferred
tx[1]=$(echo $STAT | awk '{print $2}')

# inbound
rx_bw=$( echo -e "scale = $PRECISION \n ( ${rx[1]} - ${rx[0]} ) / 256 " | bc )
# outbound
tx_bw=$( echo -e "scale = $PRECISION \n ( ${tx[1]} - ${tx[0]} ) / 256 " | bc )

# output results
echo "$rx_bw $tx_bw"

done

you can transfer it anywhere you want with netcat:

Code:

$ ./script.sh eth0 | nc remote_host 1234

providing the specified port is open on the remote_host with:

Code:

$ nc -l -p 1234

Best regards,

Igor

centosboy · 06-12-2009, 02:57 AM

Hey igor, very big thanks for that, but you see my issue is i need stats from a remote switch interface - hence me needing a tool/program that works with snmp...

kirukan · 06-12-2009, 03:52 AM

is mrtg not suitable??, by using mrtg you can get clear stats about bandwidth on each ports, new TCP and established TCP connections.

centosboy · 06-12-2009, 06:09 AM

Quote:

Originally Posted by kirukan

is mrtg not suitable??, by using mrtg you can get clear stats about bandwidth on each ports, new TCP and established TCP connections.

No, because it is not console or shell based...

Ygrex · 06-12-2009, 06:13 AM

maybe net-snmp CLI?

centosboy · 06-12-2009, 08:02 AM

Quote:

Originally Posted by Ygrex

maybe net-snmp CLI?

Well i can get the raw data using snmpwalk anyway. The data is returned in octets.
What i want is something that could convert the data the way cacti or any other rrdbased graphing tool does.
Even something like bwm-ng would do - if it could monitor remote switch ports/interfaces.

Any suggestions??
My perl isnt good enough to come up with a decent script...
Of course i could learn it properly, but i a solution in the next couple of days....

kirukan · 06-12-2009, 08:21 AM

check the output of this snmpwalk
snmpwalk -v 1 -c public 192.168.11.211 interfaces.

centosboy · 06-15-2009, 10:03 AM

Quote:

Originally Posted by kirukan

check the output of this snmpwalk
snmpwalk -v 1 -c public 192.168.11.211 interfaces.

????
That doesnt help much ...like i said, i can already gather the raw snmp data in octets using snmpwalk....
Just want to know if anyone knows of a console program that does this, but also converts the data in a format like cacti or mrtg might do it.
Anyone else??