Sequoia 15 Fortigate VPN Troubleshooting

1. Restart your ISP(Telus/Rogers/Shaw/etc..) router/modem

This will help reset/refresh all the IP addresses and clear the DNS cache as there may be some conflict with the Mac’s IP address or some outdated/corrupted network data within the router/modem itself.

2. Flush the DNS Cache

Flushing the DNS cache helps clear outdated or corrupted network data that may be causing Wi-Fi issues. This process can resolve problems with loading web pages or connecting to websites

1. Open Terminal from Applications > Utilities
2. Enter the following command: sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
3. Press Return and if prompted, enter your password
4. Reboot your device and attempt to reconnect to your network

3. Update DHCP lease

Refreshing your DHCP lease can renew your Mac’s IP address. This can potentially resolve the issue of not being able to connect to the 5G Wi-Fi connection as it may be conflicting with the IP address of another device.

1. Open System Settings > Wi-Fi
2. Select the problematic Wi-Fi connection
3. Click Details and select TCP/IP in the sidebar
4. Click the Renew DHCP Lease button

4. Set private Wi-Fi address to fixed

The private Wi-Fi address feature helps improve privacy but sometimes can cause connectivity issues, similar to the issues mentioned in Step 2. Setting it to a fixed address can potentially resolved these problems.

1. Open System Settings > Wi-Fi
2. Select Details next to your network
3. Set the private address of the network to Fixed

5. Turn off Firewall Temporarily

Other Mac users have reported that Sequoia 15 has been having issues with numerous cybersecurity devices. The Fortigate we have installed at your workplace is a cybersecurity device, more specifically, it is a firewall. This could be a reason why as to you are having various connectivity issues at your workplace. You can try disabling the Mac’s firewall temporarily and see if it resolves the issue.

1. Open System Settings > Network > Firewall
2. Toggle off the Firewall setting to deactivate it
3. Test your Wi-Fi connection to see if the problem is resolved

6. Update OS

If none of the above steps work, you may have to update to a different MacOS that is not Sequoia.