Re: MVP for a DHCP server (was Re: ISC's EoL dhcp suite, including dhcpd)

[Lloyd Parkes <lloyd%must-have-coffee.gen.nz@localhost>]

I like this idea a lot. 

I won't be running this DHCP server, but that's because this suggested
server is for normal people with normal networks. Those of us who are
not constrained by normality can and will run some other DHCP server. 

On Mon, 2025-07-14 at 13:09 +0100, Roy Marples wrote:
> Anyway, it's no secret that I've been working on a DHCP server for a
> while now and only recently found some free time to work on it.
> It's now in a useable state and I'm just going over RFC2131 with a
> fine comb to ensure it's compliant.
> It currently has (almost) zero configuration and the following
> requirements:
> 
> You need to specify a list of interfaces for it to create IP pools on
> Each interface MUST have a private address that fits (10/8, 172.16-
> 32/16,192.168/16) AND end with .1
> The first matching address found for the interface will have a pool
> generated from .10 to the maximal IP within the netmask and will be
> the Server ID
> The lease time will be an hour, T1 and T2 timers will be
> automatically generated and sent.
> Router and DNS server options will be sent (if requested) with the
> Server ID as the value.
> There is currently no persistent storage for leases.
> 
> Rationale:
> My use case is an internal router/DNS server which hosts the VM's in
> my homelab.

This also covers the use case of a home router where a VIP has the
critical requirement that the PlayStation works.

> I'm a believer that routers SHOULD have an address ending in .1 or
> ::1

I'm not super sold on ::1 for routers because I really like SLAAC. 

> In a homelab there SHOULD NOT be a large number of statically
> configured nodes, hence the pool starting at .10
> While a configuration will come at some point, I have yet to form an
> opinion on how it should look and how flexible it should be hence
> there is currently no configuration offered and the above is
> currently hard-coded.
> I find the configuration of all DHCP servers I've used pretty
> cumbersome and want something much simpler and easier.
> Infact I really don't want to think about it that much and having
> somethings "That Just Works" is a selling point IMHO hence the above.
> 
> So the question is, what is the Minimum Viable Product of a DHCP
> server for replacing ISC dhcpd in the NetBSD base system?

My personal opinion is that a minimal DHCP server can be installed on a
router and then _forgotten_ about. Someone like me who needs to
configure their DHCP server can build something from pkgsrc.

Normal people do not want to know about DHCP on their router. 

> ...
> 
> What I plan on doing next are:
> * rigourous testing and man pages
> * intial release <---- Import to NetBSD here?
> * compiles without errors and works on the same platforms dhcpcd
> supports (maybe not IllumOS)
> * DHCPv6 support (similar hard coded list above)

DHCPv6 will be a bit interesting because there won't be any links with
private IP address. Instead (at least for _normal_ people using my
_normal_ ISP) we'll want to server up DHCPv6 service in interfaces that
have DHCPv6 Delegated Prefixes.

Ngā mihi,
Lloyd