VXI-11 is a communication protocol that is still widely used by LXI instruments. It was not architected as a discovery mechanism, and calling viFindRsrc in NI-VISA never has used VXI-11 to discovery LXI instruments.
LXI a few years ago agreed to use the industry standard mDNS as a discovery mechanism. NI-VISA immediately adopted that model and since that time has automatically discovered LXI devices that support mDNS.
Calling viFindRsrc in NI-VISA returns the combined list of those devices that have been statically configured in MAX as well as those currently detected via mDNS. MAX also shows both of these.
You do not have to use MAX to add LXI devices on the local subnet that support mDNS.
You have to go into MAX to add
1) legacy LXI devices (on the local subnet) that do not support mDNS
2) legacy instruments (on the local subnet) that support the VXI-11 protocol but are not technically LXI
3) any LXI or non-LXI VXI-11 device on a remote subnet
