Hello,
I wanted to migrate my subnet from 192.168.14.0/24 to 192.168.54.0/24.
I used the alias to do so without making interruption, reconfiguring
services and clients little by little.
the DHCPd was also one of the services, and I hit this wall.
With this trouble I had to keep it for last, and keep the DHCPd setup
against 192.168.14.0/24 until the very end.
Sure enough, when I rewrote the dhcpd.conf, the hostname.igc0 to switch
to 192.168.54.0/24 and remove the alias then rebooted, everything just
fall in place.
Admittedly it is not common to do that, having 2 subnets configured on a
same interface, but there is also no explicit interdiction.
Sites like the OpenBSD Handbook (unaffiliated, I hear that) mentions it
too with the warning about route not automatically added for this
aliased subnet.
Regarding your question I was expecting DHCPd work with this aliased
subnet and provide IP to the clients.
On 11/28/2025 11:34 PM, Theo de Raadt wrote:
What do you expect dhcpd to do here?
What I've learned over the year is pretty much that interface
aliases must either be in the same subnet, OR they must be /32
addresses.
