You've never accidentally spun something up that consumes all the leases?
It's just been a couple of times, but I've definitely done it (e.g. bridged a couple of networks that shouldn't have been).
But mostly, it's the other two things: it provides me with a list of hosts active now, and if the DHCP server is subtly broken I get a sentinel signal of something being wrong earlier (and it tends to be a partial instead of complete failure).
One more bonus: if I move something to a static lease, out of the pool, it'll renumber in a reasonable time and I don't need to go kick link state to get it to request again.
Things like really big caches and really long lease times: They're good for average performance, and they can let you ride out small problems. The flip side is that they tend to mask problems and to create really big demand transients at times. The trick is always to find a good middle ground.
Modern devices will randomize MAC unless told not to when connecting / reconnecting to a wifi/Ethernet network.
When on a pretty standard /24 network subnet, if there are more than a few dozen devices coming and going, the lease table can fill up until older lease reservations expire.
You've never accidentally spun something up that consumes all the leases?
It's just been a couple of times, but I've definitely done it (e.g. bridged a couple of networks that shouldn't have been).
But mostly, it's the other two things: it provides me with a list of hosts active now, and if the DHCP server is subtly broken I get a sentinel signal of something being wrong earlier (and it tends to be a partial instead of complete failure).
One more bonus: if I move something to a static lease, out of the pool, it'll renumber in a reasonable time and I don't need to go kick link state to get it to request again.
Things like really big caches and really long lease times: They're good for average performance, and they can let you ride out small problems. The flip side is that they tend to mask problems and to create really big demand transients at times. The trick is always to find a good middle ground.
Excellent answer - new appreciation for low lease times, thank you
Modern devices will randomize MAC unless told not to when connecting / reconnecting to a wifi/Ethernet network.
When on a pretty standard /24 network subnet, if there are more than a few dozen devices coming and going, the lease table can fill up until older lease reservations expire.