Host limits for broadcast domains

Once upon a time I had my CCDA. When studying for it I found 500 hosts as the limit for a single protocol network and 250 hosts for a multiprotocol network. However, this was about 10 years ago. The main reason for those limits was that the broadcasts would impact the CPU of the hosts on the network and would thusly degrade their performance. Now that systems are much faster, plus many having dedicated processors on the NICs themselves, what are the upper limits for broadcast domains on modern networks? As it stands I'm still holding to those old 500/250 figures, but it just seems kinda silly compared to modern processing power.

Depends on your subnets.

If you are running a /24 your host limit would be 254. But if you're running say a /22 it can be 1024.

http://krow.net/dict/subnet.html

It can be higher, but still stick with ~500 as a max (lower if you can) because some old device will eventually find it's way onto the network and croak from all of the management / broadcast traffic, unless you are doing some heavy handed vlan filtering

cyr0n_k0r said:

Depends on your subnets.

If you are running a /24 your host limit would be 254. But if you're running say a /22 it can be 1024.

http://krow.net/dict/subnet.html

Click to expand...

No, what I'm talking about trancends subnetting and is only regarding the amount of hosts, period. Broadcast networks could be over 16 million hosts wide if you watned to use a /8, but the broadcasts and other overhead would cripple the network in no time. To prevent that you chop things up into manageable sizes so the hosts don't get bombared with broadcasts and other necessary overhead traffic. In the past, 500 hosts for single protocol networks and 250 hosts for mix-protocol networks was the generally accepted limits. I got those figures 10 years ago when studying Cisco material and my question was whether or not new leaps in processing power has modified those figures?