Nagios Support Forum

Hello all,

I'm brand new user of NNA and I would like to ask some quite "new users" questions here.

I have a network with 18 switches:
1 HPE FF 5700 (IFR config with 3 slaves)
4 HPE 5130
13 HPE 5120

I was wondering if I enable sflow on all Interfaces of each switches, can it slow down the network? I'm open to suggestion and best practices on what should a put in the config of the swithes Interfaces (sampling rate and other tuff)

Should I setup one port for each source in NNA? Or can all the switches send the sflow packet to NNA on the same port (6343)?

I've been looking for those information for a couples of days but got any luck on my research,

NNA version is: 2.4.3

Best regards,

I would setup a port per switch and then add a source group to aggregate them, that gives you the flexibility to see what is occurring on those specific switchces. You can technically point multiple devices to a single port if you only setup a single source but the recommendation is to setup a port per device.

I was wondering if I enable sflow on all Interfaces of each switches, can it slow down the network?

Enabling SFLOW will have an impact on the device but it should be minimal, if you're system has high CPU/utilization there is a possibility that it could theoretically slow down the networking functionality but I haven't seen anyone report that as an issue to us.

See here for a good guide on the sampling rate:

https://blog.sflow.com/2009/06/sampling-rates.html

Hello @ssax

Thanks for your reply,

Here's what I've made my setup for now (I'm open to suggestion changes)

1- On NNA I create a new source for one switch on a unique port

2- On the Switch (based on the source in NNA)
3- I add a sflow collector targetting the NNA server and the proper source Port
4- The I just need to add on all port the sflow collector and the sflow sampling

It's pretty basic setup since it's my first time I do it. But it seems to work as I get data sent to my NNA server (now I must figure out what to do with it hehehe). I'm just afraid that if I enable sflow on every port it could have an impact on my network performance.

Thank you very much for your sampling guide I'll read this very closely,

No problem, I'm glad you're seeing data.

You can see the Admin guide here:

https://assets.nagios.com/downloads/nag ... es/nna-ag/

You can see here for the Nagios Network Analyzer related KB articles:

https://support.nagios.com/kb/category.php?id=4

If you're worried about the performance impact for enabling SFLOW on all interfaces I would probably reach out to HPE and see if they recommend enabling SFLOW on all interfaces and ask them what type of impact it will have.

Hello @ssax !

FYI - I've enabled sflow on all ports on the HPE 5120 and the HPE 5130, and CPU usage on all devices went up from 1% to 4%

That's what I hoped for

One last small question, are there any good video guide I can watch for best practices and best usages (like "must know" queries and stuff) ?

Regards

That's great to hear! Thank you for posting what occurred for this, now we know!

See here if you haven't:

https://assets.nagios.com/downloads/nag ... alyzer.pdf