Trouble Shooting Network / Analyzing Traffic

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WhatTheSchmidt

Limp Gawd
Joined
Jun 4, 2007
Messages
324
I'm wondering how to go about seeing what is bogging down the internet at times. I was trying to use Wireshark but after spending a couple hours or so with it I still don't get it and maybe it's not what I want.

This is a small business and right now there are close to 20 computers on it. 3 Macs, rest windows 7 and 1 windows 8 computer. Also a few netbooks.

Hardware for the network is:

SMCd3g-ccr gateway from Comcast
8 port Trendnet switch (gigabit)
16 port Netgear switch (10/100)
D-link DWL-8600AP dualband access point

There's also a Synology NAS 10TB setup for all the network files.


At least half of the computers are wired to those switches which then go to the gateway. The rest connect to the D-link AP.


So how do I go about seeing what's going wrong to improve speeds? or tell if it's just Comcast's fault when it does slow down?
 
WhatTheSchmidt said:
I'm wondering how to go about seeing what is bogging down the internet at times. I was trying to use Wireshark but after spending a couple hours or so with it I still don't get it and maybe it's not what I want.

This is a small business and right now there are close to 20 computers on it. 3 Macs, rest windows 7 and 1 windows 8 computer. Also a few netbooks.

Hardware for the network is:

SMCd3g-ccr gateway from Comcast
8 port Trendnet switch (gigabit)
16 port Netgear switch (10/100)
D-link DWL-8600AP dualband access point

There's also a Synology NAS 10TB setup for all the network files.


At least half of the computers are wired to those switches which then go to the gateway. The rest connect to the D-link AP.


So how do I go about seeing what's going wrong to improve speeds? or tell if it's just Comcast's fault when it does slow down?
Click to expand...

Let's start with a specific description of the issue. Is it internet access speeds or local file access speeds, or what? More details = Better.
 
Nate7311 said:
Let's start with a specific description of the issue. Is it internet access speeds or local file access speeds, or what? More details = Better.
Click to expand...




Internet speeds not really network speeds.


and typical speed is more like 20Mb down / 7Mb up
 
Ok, on all machines or just one? Are any of the machines running any heavy downloading?
 
For a low cost solution, setup Untangle or SmoothWall in front of lan and behind your gateway. It'll give you some idea about what's travelling on your network and will also give you per ip/user reports. That way you can go investigate possible machine infections or torrent users.
 
Thanks systemx,

I changed a couple of the port blocking rules just now, that might have fixed it actually too. Back to normal speeds right now.

edit: it was all machines
 
systemx said:
what specific ports did you block? incoming/outgoing?
Click to expand...

3389 and some bitorrent ports even though torrents can easily be changed to diff ports.

They were rules on the Gateway firmware that were disabled because sometimes we get support that remotely accesses certain computers. I just re-enabled them.
 
Internet was slow at the end of the work day for some unknown reason. Around 7pm. My fix made it all go back to normal then it slowed down without anyone here.

Going the Untangle route on this HP intel pentium PC.
 
Can you draw up a quick diagram on how you have everything wired together? I wonder if you're running into any bottlenecking problems.

My guess is that you're overwhelming that Comcast gateway.
 
acascianelli said:
Can you draw up a quick diagram on how you have everything wired together? I wonder if you're running into any bottlenecking problems.

My guess is that you're overwhelming that Comcast gateway.
Click to expand...


sure, here you go:

3CcBR2R.jpg
 
You need to get your company to pony up some cash for a single gigabit switch that can handle all your connections. Preferably something with some decent backplane bandwidth. I imagine that people accessing that NAS aren't getting the best bandwidth, especially when you have multiple people using it simultaneously.
 
We definitely planned on replacing the 10/100 with something better but if 1 switch is that much better than using 2 I'll make sure we get a 24-40 port Gigabit switch.

Thanks
 
Regarding the number of switches, many times less is more. You want the simplest configuration that will meet or exceed your needs provided you have the right hardware for your intents and purposes. Consolidate to 1 large, robust gigabit switch, preferrably one that's managed.
 
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