Re: updated macs to high sierra, now can't scan from workcentre 6605.

Depends on what Apple broke.

If you were using FTP, Apple removed that ability, now you will need a 3rd party FTP service.

If it was a simple SMB setup, it may have killed your share, or upgraded from SMBv1 to SMBv2 or 3. IN that case, a simple firmware update could resolve it.

And if it wasn't 10.13 that broke it, it was likely Security patch 2017-01, which again, caused by Apple, and the fix is here (Excerpt below)

If you experience issues with authenticating or connecting to file shares on your Mac after you install Security Update 2017-001 for macOS High Sierra 10.13.1, follow these steps to repair file sharing:

1. Open the Terminal app, which is in the Utilities folder of your Applications folder.
2. Type sudo /usr/libexec/configureLocalKDC and press Return. 
3. Enter your administrator password and press Return.
4. Quit the Terminal app.