Why a device shows as offline, and what to check first

Availability alerts are the ones most likely to reach you before they reach me, because they usually show up as "the internet's down" or "the server's gone". In practice, offline is a status, not a diagnosis, and it has a handful of very ordinary causes.

What offline actually means

Monitoring checks in with each device on a regular schedule. If a device misses several check-ins, it is marked offline. That could mean it is broken. It far more often means:

• It was shut down or unplugged, which is entirely normal at 5pm on a Friday.
• The internet connection at that site dropped briefly.
• Wi-Fi dropped on a laptop that was carried between buildings.
• A power cut or a switched-off extension lead.
• An update was installing and the device restarted mid-check.

The first five minutes

Before anyone escalates, run through this in order:

1. Is the device actually on? Check the power light, not the screen. Monitors turn off independently. 2. Is it just this one device, or everything? One device is a device problem. Everything is a network or internet problem, and that changes who needs to fix it. 3. Check the cable. Both ends. Ethernet clips break and cleaners move desks. 4. Check the router or switch lights. No lights at all usually means power. Red or amber lights usually mean the line. 5. Restart the device once. Not repeatedly. If one restart does not bring it back, restarting again will not either.

If everything is offline and the router shows a fault, check your internet provider's status page before anything else. There is no point in me rebuilding a network configuration while an exchange is down.

What is worth telling me

When you report it, these four details save a lot of back and forth:

• Which device or devices, by name if you know it.
• What time it started.
• Whether anything changed recently, such as new furniture, a power cut, or building work.
• Whether anyone else is affected.

When it is genuinely urgent

• A server or shared line-of-business system is offline during working hours.
• More than one site is affected.
• A device is offline and you cannot physically get to it.

Call rather than email for those. Email is fine for a single laptop that dropped off overnight.

What I do at my end

Availability alerts come through with a timestamp and the affected device. Overnight ones that clear themselves are almost always a router reboot or a scheduled restart, and I will note them rather than wake anyone up. Repeat offenders get investigated properly, because a device that drops off weekly is telling you something about the cabling, the Wi-Fi coverage or the hardware.

Seeing devices drop off regularly and nobody has got to the bottom of it? Get in touch.