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I have a Billion 7401 VGP router connected to a commercial ISP (ADSL). I have configured a Linux machine to connect via MRTG regularly to collect statistics on the line. I noticed the following recently, which looked different to normal:


"4" indicates wireless, "5" indicates "bridge" and "6" indicates "ppp-channel". I'm not sure if I have configured it correctly -- I usually just look at graph "6" for the overall usage.

What I cannot explain is the usage in green on the very left of the "6" graph -- it is not reflected elsewhere in any of the other graphs. The graphs for "6" over different time-periods (not shown here) allowed me to calculate that the block of "green" data ran for about 6 hours at the same speed -- pulling down around 1GB of data. It started suddenly at the indicated speed, ran for about 6 hours, and ended almost as suddenly.

What is the "ppp-channel" and what could explain that usage if it is not reflected on the ethernet or the wireless ports? From what I can determine, only the Linux box was connected during that time and it was not downloading 1GB that I am aware of.

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If it isn't sourced from the interfaces, then it is an error, or it came from the router itself. Does your ISP show usage stats, can you tell if 1GB was actually downloaded at that time? – Paul Jan 22 '13 at 22:35
Thanks -- just thought of checking ISP usage stats now as well! – SabreWolfy Jan 22 '13 at 22:37
ISP usage stats show that ~1GB was downloaded. – SabreWolfy Jan 22 '13 at 22:39
Do you have any other services running on the router - VPN or Voip or IPTV etc? – Paul Jan 22 '13 at 23:30
I've checked what is running and I can't see how any of them downloaded a 1GB. – SabreWolfy Jan 23 '13 at 1:28

The green block portion means, the machine was abruptly disconnected from your MRTG. It's going to be plot straight and maintains that same level, so it's a block.

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The green area is not a constant block though. If you look closely you'll see variation in the graph height. – SabreWolfy Jun 30 '13 at 22:37

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