cancel
Showing results for 
Search instead for 
Did you mean: 
Create Post
Highlighted
Level 11

Can Neflow Traffic Analyzer tell me how much broadcast traffic I have on my LAN?

Jump to solution

I have multiple remote sites connected over VPNS (via WAN links) to my main site. My NPM\NTA server sits in the main site.

Can NTA give me some numbers on the amount of broadcast traffic on a remote site?

Thanks

Tags (2)
1 Solution

Accepted Solutions
Highlighted

Re: Can Neflow Traffic Analyzer tell me how much broadcast traffic I have on my LAN?

Jump to solution

Stay patient - just trying to help you here, Andrew.

If it were me trying to better identify this traffic, I would increase the sampling and port monitoring. With sFlow, the load is not invasive - and I use Procurves with all ports monitored in some instances with no hiccups.

Based on your descriptions of your remote sites, I would say your chance of excessive/measurable broadcast traffic is low, short of a malfunctioning NIC/eccentric printer.

View solution in original post

0 Kudos
15 Replies
Highlighted

Re: Can Neflow Traffic Analyzer tell me how much broadcast traffic I have on my LAN?

Jump to solution

Andrew,

are you looking to see how much local broadcast traffic is occurring on that remote site's LAN, or looking to see how much broadcast traffic is coming out of the WAN pipe? In either case, you can start - if you want - by simply searching on a broadcast address as 'Endpoint IP' on your NTA dashboard.

Highlighted
Level 13

Re: Can Neflow Traffic Analyzer tell me how much broadcast traffic I have on my LAN?

Jump to solution

Just to add to rharland's post, I'd recommend doing the endpoint filter on an Interface Detail view instead of a summary view. As was discussed recently in another thread, it seems like certain filters produce either strange or no results at all with summary views.

Highlighted
Level 11

Re: Can Neflow Traffic Analyzer tell me how much broadcast traffic I have on my LAN?

Jump to solution

Thanks for you reply : it certainly makes sense to look a the broadcast address to see broadcast traffic ! 🙂

I'm looking to see how much broadcast traffic there is on the remote LAN. I don't think they'll be any broadcast traffic on the WAN link : each site is a seperate LAN with a c class subnet and I don't think the WAN routers will pass broadcasts

I'm getting my Netflow's from a switch on the remote LAN and using the remote LAN's broadcast address. At the moment, I'm seeing nothing (in a 1 hour period) which suggest either (1) I have very low level of broadcast or (2) my sampling rate is so low I'm not seeing the broadcasts (currently set to sample 1 in 100 packets) or (3) I'm doing something wrong 😞

0 Kudos

Re: Can Neflow Traffic Analyzer tell me how much broadcast traffic I have on my LAN?

Jump to solution

Have you attempted to search on all 255s, instead of the subnet's logical broadcast? You may be surprised at what you see.

0 Kudos
Highlighted
Level 11

Re: Can Neflow Traffic Analyzer tell me how much broadcast traffic I have on my LAN?

Jump to solution

Is there a way to use wild cards for the subnets e.g.  192.168.*.255 . I've get an invalid address error when I enter it as an endpoint filter. Don't really want to enter 50+ broadcast addresses manually 😞

0 Kudos
Highlighted

Re: Can Neflow Traffic Analyzer tell me how much broadcast traffic I have on my LAN?

Jump to solution

Have you tried *.*.*.255? That will give you a breakdown of all subnet-specific broadcast addresses. Works for me, anyway.

0 Kudos
Highlighted
Level 11

Re: Can Neflow Traffic Analyzer tell me how much broadcast traffic I have on my LAN?

Jump to solution


No joy

In Flow Navigator, I'm selecting a detail view, then selecting a node and interface. I then select 'Endpoint' , type in a filter of *.*.*.255 and click 'Add Filter'. At that point I get the errror 'Please enter a valid IP addess or host name'

I'm running NTA 3.10.0 on NPM 10.5

0 Kudos
Highlighted

Re: Can Neflow Traffic Analyzer tell me how much broadcast traffic I have on my LAN?

Jump to solution

Let's try a different approach. At the Netflow summary page, go to the top right search dialog, enter *.*.*.255 and change the search context to 'Endpoint IP Address'. Perform that search. Do you receive results?

0 Kudos
Highlighted
Level 11

Re: Can Neflow Traffic Analyzer tell me how much broadcast traffic I have on my LAN?

Jump to solution

Some progress: I'm seeing some results for 169.254.255.255 and some for 255.255.255.255. But nothing for my 192.168 subnets.. 😞

0 Kudos