HP Officejet Pro 8600 keeps going offline

[dypcdiver]

HP Officejet Pro 8600 keeps going offline for some reason. If I restart it, all works normally for while.

It has been happening for about 6 weeks. I have reinstalled it several times and all seems to work for a while, then when I try to print it tells me the printer is unavailable, ie. offline. It is very annoying as it has wasted so much time as the computers are located on the floor below. All has been working with the exact same setup for several years, we have always been able to print from Mobile phones and the networked computers.

[BeemerBiker]

It is waking up from sleep and getting a different IP address than it had before.

A quick fix is to set the sleep to off or never. Access the printers embedded web page and set sleep to off or never.

If sleep cannot be disabled and the printer keeps changing its IP address then a change in the modem is necessary. The printer needs to be assigned a fixed IP address that is reserved and does not change. This is necessary on flex networks (multiple Wi-Fi booster / repeaters)

Assigning a fixed or reserved IP address is done in the modem (router) as part of DHCP configuration.

First get a network report from the printer so you know its IP address or Mac address
Log into the modem and look for the DHCP server. Find the IP or Mac address of the printer and make it a fixed IP address.

Let me know what you find out

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There is a detailed discussion of the 8600 problems here

You may want to try printing directly to the printer using Wi-Fi direct as described by Dfwestphal