Yes there's an older thread on this topic, now closed. Its conclusion is no longer up to date and is misleading. As older threads are auto-closed and there's no way to add updates, I'm starting a new topic here - if maintainers feel offended, please refactor this appropriately.
So for the record for Google: apparently, DNSmasq is no longer the DHCP service running in OpenWRT (I'm running 19.07). The software used for DHCP and DHCPv6 (including posibbly relay services) is called odhcpd . Let me quote: "odhcpd uses a UCI configuration file in /etc/config/dhcp for configuration" . The DHCP assignment range is specified using two parameters: start and limit. The defaults are 100 and 150 respectively - probably meant to correspond with a typical "C-sized" LAN subnet (well, CIDR), yielding e.g. 192.168.x.100 to 192.168.x.249 (modulo a potential off-by-one error The start and limit parameters don't seem to have entries in the LuCi GUI - which in my case doesn't matter, as the compile-time defaults are reasonable for my use. Now I know that I can number my internal servers by the first 100 addresses in the subnet.
Not sure about how to select an interface where odhcpd should or should not run, not a problem I need to solve. It probably follows hints from other configuration elements, such as the outside vs. inside interface (generally speaking).
Is this true?
DHCP 4 is handled by dnsmasq in my system, with odhcpd handling DHCP 6.
I thought this was the default configuration too, as I haven't done anything special.
Oops. You're right! Apologies for the b.s. I got the wrong idea - probably because I couldn't find any references to DHCP in the config that's clearly related to DNSmasq.
Yes it does seem that DNSmasq still serves DHCP within ipv4, after all.
The only proof that I could find, but an important one, is the output of netstat -lnp: udp 0 0 0.0.0.0:67 0.0.0.0:* 1847/dnsmasq
Curiously, the advice from the odhcpd techref entry is pretty much true: the config is stored in /etc/config/dhcp , and the file does contain a range defined as "start 100, limit 150"