alt Hacker News> I had changed the DHCP lease time on my router from the default to a really low value. I believe I had set it to 15 minutes.
What were you hoping to achieve by doing that?
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pauljara • 07/31/2025
I was trying to determine if a lease expired, if my router would immediately try to lease that same IP out to another machine on the network. It felt like it cached an expired lease mapping and would try to keep that old IP un-leased in case the original machine to which it was mapped came back online. I was just trying to better understand the behaviour.
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I like low lease times. DHCP server knows what's really on the network, and if something requests lots and lots of the pool you'll be fine in 15-30 minutes.
If things are set to a really long time, >=12 hours, you find out the next day when everything is broken (or you get alerts in the middle of the night). If you set them to a randomized 15-90m span, you get things breaking immediately when you screw up the dhcp server.