OS26 Tahoe still has AFP. OS27 Golden Gate doesn’t, and IMHO Apple’s SMB is an exceedingly poor replacement. It’s flaky. It constantly unmounts network shares. I installed a utility called AutoMount ($10 from the app store) that doesn’t really work very well. It works much better if you install the “Pro Tools” (another $3-$4, directly from the developer), but it still doesn’t do a really consistent job of keeping SMB shares mounted. Sometimes it responds in less than a minute and sometimes it doesn’t seem to notice at all when shares are unmounted. All in all, if you depend on AFP to keep a network share mounted my recommendation is that you should not upgrade to OS27.