macOS issues connecting to UCOFS

This article describes a bug in macOS 10.15.xx Catalina and later where end users are not able to connect to \\ucofs\central. It provides the details of the bug, which users are affected, and under what circumstances. Then it provides simple instructions to resolve the bug. This article is not intended to be Public, but to be a resource for the service desk and technicians that encounter the bug in the field.

Description

UCO has identified an ongoing issue where macOS 10.15.xx (Catalina) and later devices are failing to connect to UCOFS.

This is the result of a error or "bug" in macOS's implementation of the Microsoft Server Message Block (SMB) file share protocol. This directly affects how they connect to \\ucofs\central. The bug involves the macOS SMB implementation failing to properly assess the permissions of the user trying to access the share when traversing the DNS lookup of UCOFS. This results in an error incorrectly stating that the user does not have sufficient permissions to access the share. Example:

 

 

 

 

 

This is a complex bug that does not affect all users. It is most often encountered with users with access to a small selection of file shares, and is much more common when connecting to the UCO VPN, due to the added network complexity when connecting to a file share over the VPN. This does lead to cases where the bug is not present when they are working on campus, but is present when working remotely over the VPN. 

The resolution to this issue is below, and will permanently resolve the issue when accessing UCOFS, whether remotely or on campus

Instructions

1. Instruct the end user to replace "ucofs" in the file share path with "uco.local". (For Example: smb://uco.local/central/OIT/)
2. Now, instruct the user to connect to their file share as they normally would. (In most cases, this involves accessing the Finder menu > selecting Go > Connect to Server > and then typing the path to the file share, in the format shown above, into the Connect to Server dialog box)
3. The issue should now be resolved, with the user connected to their file share.