I’ve been using Observium for a while and there seems to be some discrepancies between my graphs and the upstream (my data center provides me Ethernet GigE bandwidth). For example, from around 8am to 12pm today it showed overall utilization pretty consistent well above 400Mbps.
These switches are actually trunked (2 x 3650 L3 switches). In the graph, it shows the uplink to switch #2 connectivity calculated with the total utilization (VLAN2155). This is definitely not accurate as it shouldn’t do that as far I’m concerned. Total utilization should simply be Drops #1 & #2, which covers all VLANs on both switches.
Example:
Drop #1 = 40Mbps Drop #2 = 200Mbps Uplink to Switch #2 = 130Mbps
Now as a result VLAN2155 (total utilization) is calculating not only #1 and #2 drops from the upstream, but even the trunk port labeled “Uplink to Switch #2”. I disabled polling on that uplink port and the total utilization (VLAN2155) is still far higher than what the output is for the past 24 hours from the upstream provider. They show 187Mbps past 24 hours (95th), 219M In / 202 Out. I show 266M In / 182M Out. Why is it so drastically different?
Why is Observium calculating the “uplink” to the trunked 2nd switch in the total utilization graph? This is throwing off accuracy.