The reason for this is because of an enhanced security feature added for all versions starting from Mellanox Onyx/OS 3.6.8004 and above - HTTP is disabled by default. Therefore, we are not able to reach the GUI after upgrading to 3.6.8004 and above.
There are 2 possible solutions:
1. Use HTTPS instead of HTTP to log into the GUI
2. You can enable http by using the following commands:
switch(config)# no web https ssl secure-cookie enable
switch(config)# web http enable
switch(config)# write memory
Now you can use HTTP and HTTPS connections to log into the GUI
Hope this helps
Oohh I see. Will try this then and will give an update.