MacOS connect to NAS very slow

The file may not exist and you'll be creating it.

1. Open Terminal via /Applications/Utilities/Terminal
2. Type in Terminal "sudo nano /etc/nsmb.conf" without the quotes and press Return
3. Enter your Mac password and press Return (you won't see the cursor move)
4. Type in the following:

[default]
protocol_vers_map=2

Press CTRL+X to exit and you will see:

Save modified buffer (ANSWERING "No" WILL DESTROY CHANGES) ?
 Y Yes
 N No        ^C Cancel

Type Y to answer Yes to write the changes to the file:

File Name to Write: /etc/nsmb.conf

Press Return to write the file and you'll be back to the Terminal prompt and you can type exit and press Return then quit the Terminal window.

Test out your network share, try rebooting and testing again.



What router do you have and I assume the router is providing SMB/CIFS SAMBA to share the external USB 3.0 5TB exFAT hard drive? If this is what you mean when you say NAS then the SAMBA implementation in the router may require an update. Have you checked the firmware on the router and that it is the latest version?

If that doesn't fix the problem, you might want to configure Monterey's SMB to use SMB version 2 instead of 3 which is the default SMB in Monterey. Edit the /etc/nsmb.conf by opening Terminal and typing "sudo nano /etc/nsmb.conf"

[default]
protocol_vers_map=2

You might need to reboot after you configure this file.

I would still check for updates on the router, it must be far newer on the version. Sometimes a manufacturer may have a bug in their firmware and you might need to revert but that would be extremely rare. Chances are you had to revert only temporarily until ASUS fixed whatever glitch there was at the time. The latest router firmware version should contain many fixes. I would highly recommend upgrading the firmware. If they added SMB3 to their router it will fix the problem without needing to edit this file on each Monterey system.

It depends on what version of SMB the router implemented. Try updating your firmware on the router.

To undo the SM2 setting you would delete the /etc/nsmb.conf file like this in Terminal:

sudo rm /etc/nsmb.conf

Congratulations on your trouble-shooting skills, well done! That makes a lot of sense. Most of the time issues with SMB shares being slow with Mac's involve older SAMBA servers that haven't been updated to support SMB3 or haven't been tuned for Apple devices (vfs_fruit options). You didn't mention you had multiple access points extending the range of your WiFi network. As the ASUS is at least 3 years old you might consider upgrading your WiFi solution to something that uses Mesh networking and WiFi 6. Mesh networks handle the hand-off between access points much better.

The Amazon EERO products are rather excellent for home environments. A mobile App makes it simple to setup and a starter kit comes with a base and two extenders. Several of my customers have greatly benefited by switching over to EERO Mesh WiFi 6, achieving vast improvements to their home WiFi coverage, speed, and reliability. You might also benefit from a NAS that has at least two or more disks and the Synology or QNAP brands are excellent. As are any of the FreeNAS / TrueNAS devices.

The next level up would be something like Ubiquiti's UniFi products which scale a network from small to enormous and offers much more but requires more networking knowledge.