Inteface default IPv4 netmask may be wrong in LuCI and prevents DHCP from working

Hi, I just want to share one of my observations. (Maybe a suggestion for future enhancements of luci interface.)

When you create a new inteface and configure IPv4 address (192.168.4.1 in my case) and forget to fill netmask (expecting default class C netmask will be used) it fills netmask of /32 (yes, 32) that totally confuses the DHCP server, that stops serving all other interfaces as well.

It would be nice if some meaningfull netmask is preset as default.

May be, but certainly not classful masks (like the class C you mention). They have been deprecated ten years ago (RFC 4632)