The ISP had set it up so Egress traffic on the static IP was shared and included other residential traffic, and Ingress may have been mirrored or segmented by MAC.
It was unclear, and the ISP wasn't giving us much, it took months to track down and some really clever networking tests. The Network Engineer really came through there in collecting the info we needed to have a discussion with the ISP. I mention it to save others the headache, and labor involved.
Going IPv6 native corrected a whole host of issues.
> The IP doesn't change, so technically it's static. We never said it was exclusive.
That's a pretty wild take. Was there no alternative ISP?
Not in that particular locality, the only alternative was cellular with a cradlepoint at 10x spend for 1/2 the bandwidth, and connectivity issues in bad weather.
It was buried in the fine print related to IPv4 exhaustion.
The CFO I was working with was as flabbergasted as I after we'd found out, but I've seen it a few times now, even when there is another option because of a duopoly in an area.