Problem with network traffic zabbix_agent

[broonu]

I'm using zabbix_agent to get linux network interface traffic and getting wrong values.

This is what i get with iptraf on server running the agent:

Incoming rates: 70932.1 kbits / sec

In cacti, this value is very close. In Zabbix I get this:

Incoming traffic on interface eth0 16 Aug 2013 17:59:16 94.48 Mb / s +6.98 Mb / s Graph

This is how my item is configured:

Host: Template_Linux
Name: Incoming traffic on interface $1
Type: Zabbix agent
Key: net.if.in [eth0,bytes]
Type of information: Numeric (float)
Units: b/s
Use custom multiplier: 8
Update interval (in sec) 5
Store value: Delta (speed per second)
Show value: As is

This is the server:

root@monitor:~# zabbix_server -V
Zabbix server v2.0.1 (revision 28455) (27 June 2012)
Compilation time: Jul 10, 2012 17:18:51

This is the agent:

root@router-rs:~# zabbix_agent -V
Zabbix agent v2.0.7 (revision 37436) (31 July 2013)
Compilation time: Aug  4 2013 13:47:19

Can anyone help me figure out where I am going wrong?

[Pada]

My guess is that you're comparing like instantaneous rates to average rates.

All I can suggest is that you make sure you're comparing items that use the same interval.

If you can't set the interval of both monitoring utilities to be the same, then transfer a big file at a fixed rate and then check if both monitoring utilities give the same result.

[broonu]

My guess is that you're comparing like instantaneous rates to average rates.

All I can suggest is that you make sure you're comparing items that use the same interval.

If you can't set the interval of both monitoring utilities to be the same, then transfer a big file at a fixed rate and then check if both monitoring utilities give the same result.

Thank you for your reply Pada.
The iptraf shows the traffic on the interface with an interval of 5 seconds, the same interval is configured in Zabbix item. While iptraf shows a ~70Mbps of traffic (also shown in cacti) Zabbix shows a ~90Mbps of incoming traffic (it seems that he is adding the inbound traffic to the outgoing traffic).