[andrewinardeer]

Any tips on best practices in how one can protect homelab rigs from a Carrington level event? Let's say we were given two days notice that the mother of all S4s was inbound. Just switch everything off?

What if one of my homelabs needed 100% uptime to meet my wife's SLA for messaging? Is this able to be protected?

[amluto]

Not much? As I understand it, the major effects are in very long wires. Long wires can have get massive induced currents. But your homelab is unlikely to have long wires or very large loops. Ethernet wires are limited to 100m, and unshielded Ethernet is transformer-isolated to well over 1kV.

Shielded Ethernet could plausibly have issues with induced current on the shield. PoE might be less immune than ordinary Ethernet depending on what you’re doing with it, although well-behaved devices should be isolated. If you have a cable ISP, the cable shield might get toasty, although it’s likely to be grounded close enough to your house that any damage will be upstream.

Your 100% uptime will be tricky if your ISP goes down or you lose power.

[rootusrootus]

AFAIK the risk is for long transmission lines. So your equipment at home is not really in any danger, as long as there is not a major surge on the transmission lines that makes it all the way to your house. If that happens, well, losing the home lab is probably no longer the issue.

[idatum]

Discontinue use of your telegraph system.

Perhaps though you will still be able to continue to send and receive messages despite having disconnected your power supply. [1]

[1] https://babel.hathitrust.org/cgi/pt?id=uva.x001679510&seq=40...

[tbrownaw]

Make sure you have a surge protector or ups, in case it makes the power grid go funky. Which you should have anyway.

Also, it could be a convenient excuse to upgrade to fiber internet service if you haven't already. (Yes, excuse. Equipment should have more than good enough isolation to not care.)

[johncolanduoni]

Even if you don't have fiber all the way into your house, most cable internet terminates pretty close to the home these days. It kind of has to, since bandwidth has gone way up and as a result they can't put very many subscribers on the same termination system.

We didn't really understand this kind of thing when the Carrington event happened, so nobody knows for sure, but estimates for induced voltage on long conductors are usually something on the order of 20V/km. So for a 5 km long coaxial cable, you're only talking about ~120V of induced potential difference (i.e. the same voltage as a residential plug in the US). When people are analyzing the potential damage from this kind of electromagnetic disturbance (E3 is the term you'll see, based on analysis of nuclear EMP which has other components that you don't see in geomagnetic storms regardless of severity), it's mostly about really long conductors, like on the order of 100km.