Figure 4-24. This is an example of an ifconfig command run to determine if network collisions are a problem. From both an inbound and outbound perspective, collisions are well below 1%.

It is very unlikely you will ever encounter a dropped packets problem. I have heard about this occurring only once on an Oracle system, but it was the key problem, and I suspect it has happened in other cases. Essentially, what occurs is the network card receives more packets than it can process and queues the packets for processing. However, if the network queue fills, packets are simply dropped. While this can obviously occur during a denial-of-service (DoS) attack, it could also happen on a particularly popular day for an Internet company.

There is no hard-and-fast rule of thumb for how many dropped packets is an acceptable number. I check to see if there are any dropped packets, and if so, I simply alert the network administrator and ask very clearly if the dropped packets represent a problem. If I suspect they are a problem, I note the date, time, and person I contacted. If I'm feeling particularly paranoid, I'll also email the person I contacted.