Solved

Calculate Bandwidth for a CISCO interface using SNMP

Posted on 2010-09-22
1
1,520 Views
Last Modified: 2012-05-10
Using SNMP to interrogate Cisco firewalls. I am trying to
create NMS reporting on a CISCO ASA firewall interface "OUTSODE"
I have the OID's and can interogate and get a value returned.
The OID's I need are :=
interfaces.ifTable.ifEntry.ifInOctets.#
interfaces.ifTable.ifEntry.ifOutOctets.#
# = interface number
Once I get a value returned I have been performing the following
calculation:-
(<interfaces.ifTable.ifEntry.ifInOctets.> * 8) / 1024 then divide by 1024

Although this returns a vlaue, the value is larger than 100Mb which
is the interface's max speed. I have reduced the polling frequency to
1 min.
Can anyhelp me with what I need to do to get a proper and more
meanigful value.

Thanks
0
Comment
Question by:ccfcfc
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
1 Comment
 
LVL 8

Accepted Solution

by:
Nothing_Changed earned 500 total points
ID: 33734075
interfaces.ifTable.ifEntry.ifInOctets.# is total bytes without a time dimenstion. If you want to use the method you are describing, for each of your traffic directions I'd suggest doing your poll (call it CurrPoll), keeping the last poll (call it LastPoll), and as accurately as possible track the time between your polls (as SecondsBetwPolls). Then have your monitor app use this algorithm:
((CurrPoll - LastPoll)*8)/SecondsBetwPolls
yielding for you a fairlyaccurate number on bits per second.
0

Featured Post

What is SQL Server and how does it work?

The purpose of this paper is to provide you background on SQL Server. It’s your self-study guide for learning fundamentals. It includes both the history of SQL and its technical basics. Concepts and definitions will form the solid foundation of your future DBA expertise.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

For months I had no idea how to 'discover' the IP address of the other end of a link (without asking someone who knows), and it drove me batty. Think about it. You can't use Cisco Discovery Protocol (CDP) because it's not implemented on the ASAs.…
Powerful tools can do wonders, but only in the right hands.  Nowhere is this more obvious than with the cloud.
This video gives you a great overview about bandwidth monitoring with SNMP and WMI with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're looking for how to monitor bandwidth using netflow or packet s…
Michael from AdRem Software outlines event notifications and Automatic Corrective Actions in network monitoring. Automatic Corrective Actions are scripts, which can automatically run upon discovery of a certain undesirable condition in your network.…
Suggested Courses

635 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question