`show running-config` is preceded by a header block, and one of its lines
reports the system uptime. That value necessarily differs between any two
reads, so every caller comparing consecutive configs sees a change each
time.
Measured on a GS110TPv3 under NetOrk: 876 of 894 stored config snapshots
marked as changed, one git commit and one config_changed warning per poll,
while every other device at the same installation sat between 2 and 18. The
history was worthless for that switch — a genuine change would have been
invisible among hundreds of uptime diffs.
Only the uptime line is removed. Model, firmware version, serial and MAC are
stable and belong in a config backup; a changed firmware version is exactly
the kind of change worth recording.
netgear_plus is unaffected — its get_config() returns empty strings.
The first read after this lands reports one real change, since the line
disappears from the stored config. That is unavoidable and happens once.