Using High Sierra TimeMachine for El Capitan and before

So this is not so much of a question as a solution.

After updating my main server to High Sierra, I had problems with TimeMachine not seeing the shared folder/drive.

This only occurred when the server was upgraded from 10.12 Sierra to 10.13 High Sierra.

This impacts the following client versions:

10.4 Tiger

10.5 Leopard

10.6 Snow Leopard

10.7 Lion

10.8 Mountain Lion

10.9 Mavericks

10.10 Yosemite

10.11 El Capitan

Client 10.12 Sierra as a client did not have any issues seeing the TimeMachine volumes or using them from server 10.13 Hight Sierra.

Symptoms:

• Just after upgrading the TimeMachine server from Sierra to High Sierra, all versions (I have) prior to 10.12 as a client failed in connecting to the TimeMachine share.
• The server had the appropriate folder shared, proper permissions, and the clients could mount the TimeMachine share in Finder without issues. Once mounted in the Finder, the Finder could see all the sparsebundle files but TimeMachine did NOT the folder listed as a valid TimeMachine destination.
• The server had the folder shared as AFP and SMB (also fails with just AFP and no SMB).
• The server File Sharing options had checked SMB and AFP.
• The folder on the server share had Advanced Options "Share as TimeMachine backup destination" checked with no limit on size. (This menu is available with a right-click on the folder in the Sharing System panel.)
• No combinations of these options seemed to make the TimeMachine folder appear for use when selecting the disk.

Solution:

The problem is that Sierra and High Sierra provide support for TimeMachine over SMB from OSX. Prior to these versions, TimeMachine was only using AFP. Regardless of the Sharing settings regarding SMB and AFP in either the Options button or in the share's Advanced Options, the server prefers to connect with the client using SMB.

The only solution is from the client to open Finder, Click on "Go", then "Connect to Server" (Command-K). When the "Connect to Server" dialog shows up, type in "afp://{servername}" where servername is the domain name of the server. Then choose the TimeMachine share from the list. At this point, you can open the TimeMachine preferences on the client and you will see your TimeMachine folder listed.

Hope that works for everyone and that I have been clear.