I can't tell you a thing about "blocking" or access-control-list functionality in HP Procurve switches. In general, "blocking" unwanted devices isn't a good thing. Stopping the wanted devices from getting on your network in the first place is a better idea.
To find the MAC address of an offending device, from a computer on the same subnet as that device, PING the device and then do an "arp -a" from a command prompt. You should get back something like this (on Windows):
Interface: 192.168.28.10 --- 0x6
Internet Address Physical Address Type
192.168.28.9 00-ff-22-71-a6-a2 dynamic
The MAC address is listed under the "physical address" column.
Hopefully the ProCurve switches have some functionality to allow you search the MAC address database on the switch for a given address. Do that, and the switch will tell you which port it is "seeing" that MAC address attached to.
On a Cisco switch (or a "Cisco-workalike" switch), you'd do:
show mac-address | include xxxx.xxxx.xxxx
Where the x's are the MAC address (removing the "-" between the digits that Windows reports and placing "." between each group of 4 digits).
Track down what's plugged into that port. If it's another switch, repeat the process on the other switch. If you end up with a wireless access point think about using (better) encryption to keep unauthorized parties off your network.
According to AMD's spec the destination doesn't have to be the all-ones address. It can also be the receiving station's address or a multicast address. The payload is a different story. It must be the sequence ff:ff:ff:ff:ff:ff followed by the receiving station's MAC address repeated 16 times.
The presence of absence of the station's entry in the switch's CAM table shouldn't matter in this case. If the entry isn't present the packet should be forwarded out all ports.
Best Answer
You may not be seeing what I'm going to describe, the there's a chance that you are. I've seen the symptoms you're talking about on several low-end and middle-of-the-road Netgear and Linksys switches. The switches I've seen this "crazy" behaviour happen with have been in place for awhile, working fine, but begin to flood frames out all ports. The call I normally get is "the network is slow", and subsequent bandwidth monitoring usually locates a single switch that has "gone crazy", often with its activity lights on solid, pumping out large quantities of "bogus" traffic (sometimes made up of legitimate traffic, other times seemingly random garbage).
I like Zypher's suggestion about checking on CPU utilization, but I'd also consider breaking up the "stack" (on these particular switches I don't know if a "stack" operates as a single logical unit or not) and testing each switch individually.
It seems like this problem has gotten worse in the last few years w/ no-name Ethernet switches, Linksys, and Netgear switches. I don't know if there's some silicon in common that has an issue amongst the problem switches I've seen or not. (We're recommending our Customers purchase Dell PowerConnect switches and haven't seen these kinds of problems with their switches-- yet.)