Is there a rule of thumb for the number of nodes on one subnet before you need to break it up? I know this depends on many factors, but given an average office environment with no particularly chatty devices, is there a threshold at which point you can expect a degradation in service?
Designing Cisco Networks by Diane Teare (the official CCDA coursebook), page 119 says these maximal worksation numbers per a broadcast domain:
IP - 500
IPX - 300
AppleTalk - 200
NetBIOS - 200
Mixed - 200
Thanks Milan, this is exactly the number I was looking for and the reference is especially helpful in that I can quickly obtain further info.
A much better indicator is when you approach 20% of the segments traffic being Broadcast / Multicast traffic it is time.
That sounds like a number the boss might be interested in. What's the best way to determine what percentage of the traffic is broadcast/multicast?
I use a Sniffer once the interface stats for the vlan in question start looking bad.
I also have broadcast supression configured on my uplink ports set at 20%.
Here is a link to BC suppression on a 6500
Good luck -