Is intranet a monitoring/bandwidth/QoS blind spot?

[TheScotsman]

My wife just mentioned that she's had periodic slowdowns today, and as I was starting to dig into it I realized I may have a blind spot on monitoring and bandwidth tuning. As far as I know, the bandwidth monitor and QoS only show & impact WAN traffic (please correct me if I'm wrong). I was running a backup of my son's laptop over wireless to an internal file server - that wouldn't show on the bandwidth monitor or be affected by QoS because it doesn't touch the WAN, but it could be soaking up bandwidth and slowing things down for other wireless users. Is there anyway to easily see that "in the house" bandwidth usage?

Running 388.2 beta 1 (yeah, I know beta 2 is out, haven't gotten it loaded yet!) on a GT-AXE11000.

 

[ColinTaylor]

Traffic Analyzer - Traffic Monitor and switch to the Wired or Wireless interfaces.

 

[Viktor Jaep]

Traffic Analyzer - Traffic Monitor and switch to the Wired or Wireless interfaces.

Or take a look at the results from RTRMON.

And yes, @TheScotsman... if you are consuming most of the WiFI bandwidth doing a backup, that will have an effect on your wife trying to get a slice of that bandwidth to get out through the WAN.

 

[Justinh]

I think the OP realizes that internal traffic affects WAN<>LAN bandwidth. He is trying to diagnose where the bandwidth is being consumed.

Colin, for the dunce like me, can you expand on your response? Are you saying he needs to use "Traffic Analyzer" or that is does capture LAN<>LAN traffic?

 

[ColinTaylor]

Colin, for the dunce like me, can you expand on your response? Are you saying he needs to use "Traffic Analyzer" or that is does capture LAN<>LAN traffic?

No, look at the Traffic Monitor tab. It doesn't show individual clients, but it does show the total bandwidth per interface. It might not register traffic between two clients connected to the same interface (depending on router model), but it should at least register traffic between different interfaces, e.g. 2.4GHz to wired.

 

[Viktor Jaep]

I think the OP realizes that internal traffic affects WAN<>LAN bandwidth. He is trying to diagnose where the bandwidth is being consumed.

Like I said ... RTRMON can give you that info.

 

[TheScotsman]

Thanks all - @Justinh is right, I know that internal traffic affects the WAN<>LAN bandwidth (or more specifically in this case, the internal traffic is so high that the WAN bandwidth is kind of irrelevant); and in this case it was easy to diagnose since I was the only one other than her generating traffic, it's more a prep exercise for when the kids are also home so blame can be assigned as needed. I did verify that the internal traffic DOES show up on the Traffic Analyzer-Traffic Monitor tab, so that could be useful in realtime to find which band is hogging traffic (tks @ColinTaylor) and then hunt down the offending client(s) (looks like RTRMON would be ideal for that, thanks @Viktor Jaep !)

Would turning on airtime fairness be worthwhile to damp the impact of this sort of thing? I'd gotten the impression from other forum posts that it's a bit of a double-edged sword and can adversely impact gaming and streaming. Some of the high-volume backup traffic can be unpredictable - for machines on the wire it's all scheduled off-hours, but for the wireless laptops it's set to run opportunistically (i.e. if a backup-covered laptop shows up on the network and hasn't been backed up in the last <n> hours, grab an incremental while it's visible ...)

 

[TheScotsman]

Just realized another thing to test is how the Traffic Analyzer-Traffic Monitor tab handles AiMesh - my guess would be that traffic for a wireless client connected to an AiMesh node that is using a wired backhaul is going to show up as wired traffic, if at all. @Viktor Jaep how does RTRMON handle AiMesh - I'm assuming I'd need to install a copy on each AiMesh node as well as the main router and SSH to the one I'm interested in looking at stats for?

 

[Viktor Jaep]

Just realized another thing to test is how the Traffic Analyzer-Traffic Monitor tab handles AiMesh - my guess would be that traffic for a wireless client connected to an AiMesh node that is using a wired backhaul is going to show up as wired traffic, if at all. @Viktor Jaep how does RTRMON handle AiMesh - I'm assuming I'd need to install a copy on each AiMesh node as well as the main router and SSH to the one I'm interested in looking at stats for?

I'm not quite sure about that, @TheScotsman... never attempted or heard of anyone try to figure this out along with AiMesh... Not knowing if AiMesh transfers locally across the router, or if it does have to make it all the way back to the master router... or depending on where the clients are located.

It may make things easier to just run the iftop command on your different routers to see if you can find the traffic you're looking for. That's basically the tool that RTRMON uses and puts it in a pretty format. You would just need to specify the interface, and would suggest using br0, since that would capture all traffic coming in over the wifi, and ending up at a different location.

iftop -i br0

 

[ColinTaylor]

It may make things easier to just run the iftop command on your different routers to see if you can find the traffic you're looking for. That's basically the tool that RTRMON uses and puts it in a pretty format. You would just need to specify the interface, and would suggest using br0, since that would capture all traffic coming in over the wifi, and ending up at a different location.

iftop -i br0

br0 won't work for LAN to LAN traffic as it's bridged not routed (maybe it worked for the pre-HND models, I can't remember). You'd have to look at the stats for the individual interfaces.