Discussion: host matching (generated MAC addresses non-unique) #602

Background: Cisco UCS blade centers generate mac addresses from a pool. Uniqueness occurs at the site but not across sites. city-ucs-blade has mac 00:25:b5:00:00:xx and city2.ucs-blade could have the same xx.

Currently the code does an initial inventory match using collected object data. Then, physical NIC MAC matching across the inventory (no site filter). Then serial-number matching. Then asset tag.

In my case, this causes a churn:

2026-10-26 14:31:02,758 - INFO: Device 'dal-blade9' attribute 'name' changed from 'tor-blade8' to 'dal-blade9'

and so on. I propose a few solutions and can work up a PR, but, I'd like to get some my current ones merged in first so I don't have to keep updating multiple branches in order to keep testing.

1. Move serial number matching before mac address matching. This isn't a perfect solution because a match still might not occur and fall through to the mac anyway. Needs some guardrails applied potentially.
2. Scope the mac matching to the site. (possibly rejecting conflicting serials?)

I'm almost liking both as the best overall answer. Serial number is a stronger unique match anyway, but I can still see ways to fall through and hit the same situation.