Nessus scanning

[Bill Saragoza]

Nessus 1.2.0 on red Hat 7.2 Let's say I scan I range of hosts in the remote network that are behind firewall. I can ping all of them but it looks like icmp is the only traffic allowed in. In my scan configuration I disable port scanning and enable all plugins, in the result window of NessusWX after the scan I see no hosts at all...is that normal, considering that only icmp is allowed for those hosts on remote firewall? P.S> I see only 2 servers in the report cause they have http open and I don't see the rest of the hosts.(But I can ping all of them)