HP and CA both support IP, IPX, DMI and Layer 2 discoveries. We didn't evaluate IPX discovery, though we didn't turn it off and did see IPX results. Both products support the combination of IP and IPX discoveries, with a preference for IP when both are available on a network.
We didn't take into consideration high-availability or scalability functions in the architecture of the products we tested, as our focus was on managing the 1,000 interfaces. Scalability, while important (and available with some of the products), isn't as important as getting an immediate network-management bang. Our $10,000 limit also put high availability on the back burner. Still, it's easy to see how having redundant servers, distributed pollers, support for external third-party databases and the ability to administer parts of the system without rebooting would be valuable as your network grows.
Orion's Lucky Star
SolarWinds.Net's Orion Network Performance Monitor is our Editor's Choice. The software quickly got down to managing our network with good out-of-the-box functionality. It had enough depth and flexibility to give us a good handle on how the network was performing, without being overly complicated. We aren't exactly jumping up and down about it, but given the modest dollars and time Orion required, the product is a pretty sure bet.
Our Best Value award goes to WhatsUp Gold from Ipswitch, which also has solid features and administration that will reap immediate rewards. Costing less than my kids' daily lunch money (a measly $1.19 per day over five years), it's not going to grow with you, but it won't let you down either. SNMPc from Castle Rock had the second best price and great SNMP MIB support without being overly difficult to administer. Though it did go a little nuts when discovering the network and had just average fault and performance management.