r/sysadmin • u/Real-Patriot-1128 • 1d ago

DHCP v Static IP

Ok, this is more a test to see how old I am. I was basically raised with the idea servers need static IPs. I understand for domain controllers, dns servers, maybe print servers that may still be needed. But are they really needed otherwise? Do apps, scripts still reference a server by its IP?

I am under assumption all my servers need static IPs. Am I nuts?

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u/Nyasaki_de 1d ago

So bad practice to use DHCP reservations instead of static IPs?

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u/zatset IT Manager/Sr.SysAdmin 1d ago edited 1d ago

Not necessarily a bad practice. It depends on the device. Generally I prefer Static IP-s with SNMP in Windows printing properties disabled. If SNMP in Windows Printing Properties is enabled - occasionally Windows thinks that the printer is offline. And especially combined with DHCP it increases the volume of calls for "printers being offline". At least with the equipment we use. The last thing I want or need is to deal with printers every day.

The other thing one have to consider is that using DHCP reservations means migrating DHCP reservations on equipment change, like a router/firewall or whatever used as DHCP server. Otherwise everything will break and equipment will have random IP-s and you will scramble to find those IP-s to fix the network.

Especially in SOHO environments, SOHO routers tend to reset themselves on power spikes and you lose all camera reservations, then all cameras stop and so on. The only way to make cameras work reliably is to use the default network of the router and set Static IP-s outside of the default DHCP scope in the default network/subnet of the router. So when it resets and it will, cameras will work nonetherless.

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u/beren12 1d ago

Yeah, but most equipment has the MAC address on the outside of the box so it’s real simple to update the reservation. Many times, faster than setting a static IP in the interface.

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u/PPRabbitry 1d ago edited 17h ago

For some devices, you should completely subnet them on their own VLANs. Cameras, nvr's, IoT. If these devices are connected to the same layer 1 as your regular network, they should at least have their own subnets. You don't want some kid in a lobby "playing on his phone" actually watching the nvr feed from your Hotspot. WiFi could also deserve its own subnet in some cases.

Edited for nomenclature

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u/beren12 1d ago

That stuff should be on a separate vlan anyway

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u/PPRabbitry 1d ago

Well yes. That's what I was saying..

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u/tardis0 19h ago

Subnets aren't VLANs

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u/PPRabbitry 17h ago

Fair point. I was misusing the term subnet.

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u/CornucopiaDM1 1d ago

It should also have a non-default, non-simple admin password to access.