Strange Traffic calculation in LibreNMS?

RouterOS General
1

Hi Mikrotik

Recently installed LibreNMS into my Proxmox LXC container, and all fine. Enabled SMTP on My RB5009, configured community , IP from LibreNMS etc.. And all works fine, but traffic calculation is something weird.. For example..

From 1-st Jan 2026 to 27.01.2026 - 8.07GB Total

1
11896Ă—952 148 KB

From Last Month 2025-12-27 21:35 to 2026-01-27 21:35 - 6.67GB Total

2
21920Ă—1080 254 KB

How is possible from 1-st to 27-nd to have 8.07GB and from 27.12.2025 to 27.01.2026 to have 6.67GB Total?

I have setup LibreNMS yesterday.. This is SNMP export:

[admin@MikroTik] /snmp> export
# 2026-01-27 21:43:44 by RouterOS 7.20.7
# software id = 0Q24-H92Q
#
# model = RB5009UPr+S+
# serial number = XXX
/snmp community
set [ find default=yes ] addresses=192.168.88.30/32 encryption-protocol=AES name=librenms
/snmp
set enabled=yes location=XXX
2

I can replicate a similar discrepancy on a LibreNMS install which is not running via container/app on RouterOS. If I look at ether1 on my RB5009 which was reset with a new config in early November, I see these numbers:

Range: 2025-10-01 00:01 to now: 1.90TB

Range: 1 year from 2025-01-27 15:55: 1.88TB

A 2 year view also shows 1.90TB. I would expect these to all be the same since they all include 100% of the operational days. Like you I have an empty graph on the left side of each graph. I don’t see any discrepancy on any views with a full set of polling data (full graph left to right).

There may be something funny happening when it’s calculating a range that includes un-polled intervals. Or maybe different duration chunking and averaging depending on the range. You might be able to examine each RRD command that’s generating the output to see what’s up. Beyond that, this looks to me like a question to raise on the LibreNMS forum.

1 Like
3

To repeat what I said in the issue report here. This is not a LibreNMS bug. This is a behavior of rrdtool.

Several RRA are set up for long term metric storage and consolidation. When you increase the time range it selects a different RRA which has been consolidated.

If on of the time ranges contains partial data, that can really throw off calculations.

For more info check LibreNMS’s default RRA definition and the rrdtool documentation.

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