If you use SNMP to do discovery does it work?

Steps to discover device

1. Ensure switches are configured properly and OMNM server can ping switches and switches can ping OMNM server
2. Log into OMNM server page
3. From the Home screen select Resource Discovery on the right side.
4. Click on Find your inventory and assets fast and easy.
5. In Quick Discovery Type in the IP addresses of each device in the range format.
6. Under Select Authentication Click on Create New In the Add new Authentication to Resource Discovery screen.
7. Type in Name for auth type (User name is common) for the Authentication Name.
8. Select Protocol Type [telnet or SSH]
9. Type in the User ID as [Switch configured user]
10. Type in the User Password as [Switch configured password for above user]
11. Type in the Enable ID leave blank.
12. Type in the Enable Password as [Switch configured enable password]
13. Click Apply.
14. Add SNMP Authentication.
15. Under Select Authentication click on Create New In the Add new Authentication to Resource Discovery screen.
16. In Authentication Name provide a name [SNMP or Community name is common]
17. Select Protocol Type [That is used SNMPv2c is most common]
18. Under Read Community type in [community configured on switches].
19. Under Write Community type in [community configured on switches].
20. Under Trap Community type in [community configured on switches].
21. Click Apply
22. Click Execute to start the Discover Process.
23. Click Discover
24. Watch for each of the devices to be discovered.
25. If any of the devices fail to be discovered check IP’s
26. Check authentication on OMNM, telnet, snmp.
27. Check configurations on each device.

Click close on the Discovery window

Right, the devices are being discovered and added, but the discovery action is sending a command that is not supported by those switches. Therefore, the MAC address of those devices is not being captured during discovery and I do not see a way to populate the MAC address for those devices manually. IP Address, software version, model, and pretty much all other information is captured appropriately during discover. Any ideas?

What version of OMNM are you using? Can you private message me the service tag of one of the switches?