In theory it's fine to have multiple DHCP servers as long as they don't step on each other. But in reality a bunch of the things mentioned in this post are ways for the network to be hosed. Unfortunately, enough LANs are semi-hosed that it's worth working around known problems.
At work I manage a network with two DHCP servers. One is a dnsmasq that assigns the IP address, hostname, and basic network parameters to all network devices, and the other is a LTSP server (https://ltsp.org/) that provides network boot images only for certain devices that require it. It might not look pretty, but it works really well.
What really matters is that there's a coherent policy for assigning addresses, which is absolutely compatible with having multiple DHCP servers on the same subnet (e.g. each server configured to hand out non-overlapping IP ranges).
It's less about the IP ranges they're giving out not overlapping and more about the requests that they respond to not overlapping (or at least that they don't contradict one another). The classic 'someone plugged a consumer wifi router into the office/university network' problem often is made worse because the consumer wifi router gives out different addresses.
You don’t have to have one. My first LAN didn’t. I had no idea what I was doing and picked 17.0.0.0 addresses for local ones and I couldn’t connect to Apples website.
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There'd better be or your network is probably hosed.
In theory it's fine to have multiple DHCP servers as long as they don't step on each other. But in reality a bunch of the things mentioned in this post are ways for the network to be hosed. Unfortunately, enough LANs are semi-hosed that it's worth working around known problems.
At work I manage a network with two DHCP servers. One is a dnsmasq that assigns the IP address, hostname, and basic network parameters to all network devices, and the other is a LTSP server (https://ltsp.org/) that provides network boot images only for certain devices that require it. It might not look pretty, but it works really well.
https://datatracker.ietf.org/doc/html/draft-ietf-dhc-failove...
What really matters is that there's a coherent policy for assigning addresses, which is absolutely compatible with having multiple DHCP servers on the same subnet (e.g. each server configured to hand out non-overlapping IP ranges).
It's less about the IP ranges they're giving out not overlapping and more about the requests that they respond to not overlapping (or at least that they don't contradict one another). The classic 'someone plugged a consumer wifi router into the office/university network' problem often is made worse because the consumer wifi router gives out different addresses.
Windows supports dhcp failover, where multiple dhcp servers can exist on the same subnet.
That works mostly, you'll have problems if you have duplicate IP addresses though.
Well, consumer Windowses (XP Home? It’s been a while) used to hose networks because they were "helpfully" running their own DHCP server.
You don’t have to have one. My first LAN didn’t. I had no idea what I was doing and picked 17.0.0.0 addresses for local ones and I couldn’t connect to Apples website.