Openmanage Net Manager - quick discovery problem

Hello,

I recently installed the Openmanage Network Manager mainly to access Dellpower Connect 6248P switches.

Problem is that when running a quick discovery against 3 switch stacks that we have here on the network we get the following " 3 address(es) did not respond to Ping"

Switch Stack #1 contains 4 Powerconnect 6248P switch.

Switch stack #2 contains 2 Powerconnect 6248P switchs.

Switch stack #3 contains 2 Powerconnect 6248P switchs.

ICMP is not allowed on these switch stacks so therefore no pinging allowed to them.

Can OMNN collect info on these switches in another method like SNMP or HTTP?

Do I need to turn on ICMP on the switch stacks in order to get OMNN to collect data?

Thanks