Deployment Architecture

Network Traffic with Stream

fludorf_splunk
Splunk Employee
Splunk Employee

Hi!

I would like to monitor to total amount of traffic leaving and entering my home network. I have the following setup:
Internal network: 192.168.1.*
Firewall (internal NIC): 192.168.1.1
Firewall (external NIC): 192.168.178.23
DSL Modem: 192.168.178.1

I have Stream installed on the firewall 192.168.1.1.

I would like to see the following:
Total MB uploaded for a defined time
Total MB downloaded for a defined time

The queries I am using are:
Upload: sourcetype="stream:ip" dest_ip!="192.168.1.*" | stats sum(bytes_in) as bytes | eval MB=round((bytes/(1024*1024)),2) | table MB

Download: sourcetype="stream:ip" dest_ip!="192.168.1.*" | stats sum(bytes_out) as bytes | eval MB=round((bytes/(1024*1024)),2) | table MB

When I cross compare the Up and Download statistics on my DSL router for a specific time to what I get with my queries, I get very different numbers.

Any ideas?

Thanks!

Tags (1)
0 Karma

nickhills
Ultra Champion

Ah, ok I see the error in my suggested query, however....
If your firewall has a dedicated nic connected to the router, you could just tell stream to monitor all traffic on that nic. Then you won’t need to filter anything.
http://docs.splunk.com/Documentation/StreamApp/6.3.0/DeployStreamApp/ConfigureStreamForwarder#Use_XM...

If my comment helps, please give it a thumbs up!
0 Karma

nickhills
Ultra Champion

Well without digging into your exact setup, i think you might be better in looking at traffic to/from specific IPs (rather than ignoring traffic to a range)

Try changing your queries to:

sourcetype="stream:ip" dest_ip="192.168.178.1" | stats sum(bytes_out) as bytes | eval MB=round((bytes/(1024*1024)),2) | table MB

sourcetype="stream:ip" src_ip="192.168.178.1" | stats sum(bytes_out) as bytes | eval MB=round((bytes/(1024*1024)),2) | table MB

Edit: Also - how wild, is 'wild'? and in which direction is it different?

If my comment helps, please give it a thumbs up!
0 Karma

fludorf_splunk
Splunk Employee
Splunk Employee

Hi, thanks for getting back to me.

I tried your suggestion but this only provides traffic to/from that specific IP rather than via it.

Examples of differences:

Original queries:
In: 462 MB
Out: 8770 MB

Suggested queries
In: 0 MB
Out: 27 MB

DSL Router Information:
In: 435
Out: 4936

Thanks

0 Karma
Get Updates on the Splunk Community!

Introducing the Splunk Community Dashboard Challenge!

Welcome to Splunk Community Dashboard Challenge! This is your chance to showcase your skills in creating ...

Built-in Service Level Objectives Management to Bridge the Gap Between Service & ...

Wednesday, May 29, 2024  |  11AM PST / 2PM ESTRegister now and join us to learn more about how you can ...

Get Your Exclusive Splunk Certified Cybersecurity Defense Engineer Certification at ...

We’re excited to announce a new Splunk certification exam being released at .conf24! If you’re headed to Vegas ...