Trying to use network for back-up

It's not clear whether the 3 Macs can back up to the TC. If not, post back with details.

What is the "network drive?" If it's a USB connected to the TC, you should be able to back up to it, as long as it's formatted properly. See #Q2 in [Using Time Machine with a Time Capsule|http://web.me.com/pondini/Time Machine/TimeCapsule.html] (or use the link in *User Tips* at the top of this forum).

If it's a NAS (Network Attached Storage) device, it may or may not be compatible with Time Machine. See the pink box in #2 of [Time Machine - Frequently Asked Questions|http://web.me.com/pondini/Time_Machine/FAQ.html] (or use the link in *User Tips* at the top of the +Time Machine+ forum).

Mark Bateman1 wrote:
The 3 mac's are backing up fine on the TC.

Cool.

I also have an Ubuntu Server running NetAtalk and Avahi (Bonjour) I used to be able to select the disk on the Ubuntu server as a Time Machine back-up destination.

I don't think that's a supported destination. If it is, you should be able to mount it via the Finder, then it should appear in the list of possible destinations in +Time Machine Preferences > Select Disk.+

If not, you'll need some sort of hack to use an unsupported device, and those are often unreliable.