With the following setup: port=0 interface=eth0 bind-interfaces dhcp-range=192.168.1.2,192.168.1.254
I get: # /usr/bin/netstat -tunpevaW | grep dnsmasq udp 0 0 0.0.0.0:67 0.0.0.0:* 0 19371604 3877093/dnsmasq which contradicts your own documentation (please read until the end): # If you want dnsmasq to listen for DHCP and DNS requests only on # specified interfaces (and the loopback) give the name of the # interface (eg eth0) here. # Repeat the line for more than one interface. # interface= # On systems which support it, dnsmasq binds the wildcard address, # even when it is listening on only some interfaces. It then discards # requests that it shouldn't reply to. This has the advantage of # working even when interfaces come and go and change address. If you # want dnsmasq to really bind only the interfaces it is listening on, # uncomment this option. About the only time you may need this is when # running another nameserver on the same machine. # bind-interfaces So, bind-interfaces is not applied. Why is it a problem? In cases where there are multiple DHCP servers, this dnsmasq issue prevents the coexistence with these other servers as it binds to **all** ionterfaces and prevent other servers from listening on the interfaces they were setup for. A perfect example is libvirtd: this issue prevents libvirtd from starting its one instance of dnsmasq over virbr0 (for instance). Cf. https://wiki.libvirt.org/Libvirtd_and_dnsmasq.html. FYI, this failed behavior did not exist in Ubuntu noble. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2098119 Title: dnsmasq opens DHCP server ports on all interfaces instead of just on the interface(s) defined in interface= setting To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/dnsmasq/+bug/2098119/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
