Monitoring time capsule bandwidth via MRTG?

Question

I purchased a time capsule a few months back and have just got MRTG up and running to monitor bandwidth via SNMP. There is a thread here that suggests this is possible:
https://discussions.apple.com/message/9410927#9410927
Running snmpwalk on my time capsule shows 12 different devices:
ifDescr.1 = STRING: mgi0
ifDescr.2 = STRING: mgi1
ifDescr.3 = STRING: bwl0
ifDescr.4 = STRING: bwl1
ifDescr.5 = STRING: lo0
ifDescr.6 = STRING: wlan0
ifDescr.7 = STRING: wlan1
ifDescr.8 = STRING: wlan2
ifDescr.9 = STRING: wlan3
ifDescr.10 = STRING: bridge0
ifDescr.11 = STRING: bridge1
ifDescr.12 = STRING: rxq0
However, I've tried monitoring each and every one of these devices and it doesn't seem any of these represents the WAN port. For example, I can pull 1000kB/sec down on two separate devices (one connected via Wi-Fi and one connected via ethernet) and none of these will show 2000kB/sec, so I'm sort of at a loss. Do the new time capsules just no longer support monitoring bandwidth on the WAN port? Anyway around this?
Thanks!

Answer 1

I just had to figure this out on a Time Capsule, and since there is a lack of information on the Internet about the new models I did a bunch of trial and error.
Here's what I found:
They report the wrong interface speeds via SNMP, which is why cfgmaker is confused about the speeds.
They do SNMPv2 just fine.
cfgmaker is otherwise accurate.
I believe the interfaces are:
mgi0 LAN
mgi1 WAN
bwl0 2.4 Ghz Radio
bwl1 5.0 Ghz Radio
lo0 loopback
wlan0 2.4 Ghz Network
wlan1 5.0 Ghz Network
pppoe0 PPP Over Ethernet Client          
bridge0 Internal bridge between wired an wireless
gif0 6in4 Tunnel
stf0 6to4 Tunneling
The architecture seems to be that mgi0 is attached to the 3-port switch for the LAN ports, so they all aggregate under that one interface.  bwl0/wlan0 always report the same bits for 2.4G clients, bwl1/wlan1 the same bits for 5G clients.  bridge0 bridges between mgi0, bwl0/wlan0, and bwl1/wlan1.  I don't use pppoe, so I can't confirm what that shows, but I assume it's the traffic _inside_ the PPPOE session on the WAN, if used.  gif0 is 6in4 tunneling, and stf0 is 6to4 tunneling.
The only thing I'm unsure about is the WiFi interfaces are set to 300Mbps/max in this config.  I am unclear if this box can do 450Mbps throughput with the right clients.
A sample MRTG config file is below.
WorkDir: /path/to/your/files
Options[_]: growright,bits
WithPeak[_]: ymw
YSize[_]: 200
XSize[_]: 600
### Interface 1 >> Descr: 'mgi0' | Name: '' | Ip: '' | Eth: '' ###
Target[10.0.1.1_1]: 1:[email protected]:::::2
MaxBytes[10.0.1.1_1]: 125000000
Title[10.0.1.1_1]: Traffic Analysis for mgi0 -- timecapsulename
PageTop[10.0.1.1_1]: <h1>Traffic Analysis for mgi0 -- timecapsulename</h1>
### Interface 2 >> Descr: 'mgi1' | Name: '' | Ip: '169.254.147.241' | Eth: '' ###
Target[10.0.1.1_2]: 2:[email protected]:::::2
MaxBytes[10.0.1.1_2]: 125000000
Title[10.0.1.1_2]: Traffic Analysis for mgi1 -- timecapsulename
PageTop[10.0.1.1_2]: <h1>Traffic Analysis for mgi1 -- timecapsulename</h1>
### Interface 3 >> Descr: 'bwl0' | Name: '' | Ip: '' | Eth: '' ###
Target[10.0.1.1_3]: 3:[email protected]:::::2
MaxBytes[10.0.1.1_3]: 37500000
Title[10.0.1.1_3]: Traffic Analysis for bwl0 -- timecapsulename
PageTop[10.0.1.1_3]: <h1>Traffic Analysis for bwl0 -- timecapsulename</h1>
### Interface 4 >> Descr: 'bwl1' | Name: '' | Ip: '' | Eth: '' ###
Target[10.0.1.1_4]: 4:[email protected]:::::2
MaxBytes[10.0.1.1_4]: 37500000
Title[10.0.1.1_4]: Traffic Analysis for bwl1 -- timecapsulename
PageTop[10.0.1.1_4]: <h1>Traffic Analysis for bwl1 -- timecapsulename</h1>
### Interface 5 >> Descr: 'lo0' | Name: '' | Ip: '127.0.0.2' | Eth: '' ###
Target[10.0.1.1_5]: 5:[email protected]:::::2
MaxBytes[10.0.1.1_5]: 125000000
Title[10.0.1.1_5]: Traffic Analysis for lo0 -- timecapsulename
PageTop[10.0.1.1_5]: <h1>Traffic Analysis for lo0 -- timecapsulename</h1>
### Interface 6 >> Descr: 'wlan0' | Name: '' | Ip: '' |
Target[10.0.1.1_6]: 6:[email protected]:::::2
SetEnv[10.0.1.1_6]: MRTG_INT_IP="" MRTG_INT_DESCR="wlan0"
MaxBytes[10.0.1.1_6]: 37500000
Title[10.0.1.1_6]: Traffic Analysis for wlan0 -- timecapsulename
PageTop[10.0.1.1_6]: <h1>Traffic Analysis for wlan0 -- timecapsulename</h1>
### Interface 7 >> Descr: 'wlan1' | Name: '' | Ip: '' |
Target[10.0.1.1_7]: 7:[email protected]:::::2
SetEnv[10.0.1.1_7]: MRTG_INT_IP="" MRTG_INT_DESCR="wlan1"
MaxBytes[10.0.1.1_7]: 37500000
Title[10.0.1.1_7]: Traffic Analysis for wlan1 -- timecapsulename
PageTop[10.0.1.1_7]: <h1>Traffic Analysis for wlan1 -- timecapsulename</h1>
### Interface 8 >> Descr: 'pppoe0' | Name: '' | Ip: '' | Eth: '' ###
Target[10.0.1.1_8]: 8:[email protected]:::::2
MaxBytes[10.0.1.1_8]: 125000000
Title[10.0.1.1_8]: Traffic Analysis for pppoe0 -- timecapsulename
PageTop[10.0.1.1_8]: <h1>Traffic Analysis for pppoe0 -- timecapsulename</h1>
### Interface 9 >> Descr: 'bridge0' | Name: '' | Ip: '' | Eth: '' ###
Target[10.0.1.1_9]: 9:[email protected]:::::2
MaxBytes[10.0.1.1_9]: 125000000
Title[10.0.1.1_9]: Traffic Analysis for bridge0 -- timecapsulename
PageTop[10.0.1.1_9]: <h1>Traffic Analysis for bridge0 -- timecapsulename</h1>
### Interface 10 >> Descr: 'gif0' | Name: '' | Ip: '' | Eth: '' ###
Target[10.0.1.1_10]: 10:[email protected]:::::2
MaxBytes[10.0.1.1_10]: 125000000
Title[10.0.1.1_10]: Traffic Analysis for gif0 -- timecapsulename
PageTop[10.0.1.1_10]: <h1>Traffic Analysis for gif0 -- timecapsulename</h1>
### Interface 11 >> Descr: 'stf0' | Name: '' | Ip: '' | Eth: '' ###
Target[10.0.1.1_11]: 11:[email protected]:::::2
MaxBytes[10.0.1.1_11]: 125000000
Title[10.0.1.1_11]: Traffic Analysis for stf0 -- timecapsulename
PageTop[10.0.1.1_11]: <h1>Traffic Analysis for stf0 -- timecapsulename</h1>