Hi,
I am using Beaglebone Black with debian recent os. I am trying to get the dhcp server setup using dnsmasq. It is installed and the service runs. I plug either a windows pc or and ubuntu pc directly in as my client device on eth0.
I cannot get the DHCP_DISCOVER message to be seen by dnsmasq hence no ip address is offered 
I am not interested in the DNS side of it I am happy with ip addresses.
Some basic info
root@beaglebone:/etc# ifconfig eth0
eth0 Link encap:Ethernet HWaddr 90:59:af:50:2d:73
inet addr:192.168.2.1 Bcast:192.168.2.255 Mask:255.255.255.0
inet6 addr: fe80::9259:afff:fe50:2d73/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:312 errors:0 dropped:0 overruns:0 frame:0
TX packets:41 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:73847 (72.1 KiB) TX bytes:7223 (7.0 KiB)
Interrupt:40
/etc/network/interfaces (the important bit)
auto eth0
#iface eth0 inet dhcp
iface eth0 inet static
address 192.168.2.1
netmask 0.0.0.0
network 192.168.2.0
netmask 255.255.255.0
gateway 192.168.2.1
/etc/dnsmasq.conf
user=root
#domain-needed
bogus-priv
domain=diag.net
#expand-hosts
local=/diag.net/
no-resolv
#no-poll
interface=eth0
listen-address=127.0.0.1
listen-address=192.168.2.1
#bind-interfaces
dhcp-range=eth0,192,168,2,2,192.168.2.10,200
dhcp-option=eth0,3,192.168.2.1
#dhcp-option=eth0,6,192.168.2.1
#dhcp-authoritative
log-facility=/var/log/dnsmasq.log
log-queries
log-dhcp
netstat
root@beaglebone:/etc# netstat -plunt
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:53 0.0.0.0:* LISTEN 721/dnsmasq
tcp 0 0 127.0.0.1:3350 0.0.0.0:* LISTEN 974/xrdp-sesman
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 977/sshd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1338/exim4
tcp 0 0 0.0.0.0:3389 0.0.0.0:* LISTEN 938/xrdp
tcp6 0 0 :::8080 :::* LISTEN 1226/apache2
tcp6 0 0 :::80 :::* LISTEN 1/systemd
tcp6 0 0 :::53 :::* LISTEN 721/dnsmasq
tcp6 0 0 :::22 :::* LISTEN 977/sshd
tcp6 0 0 :::3000 :::* LISTEN 1/systemd
tcp6 0 0 ::1:25 :::* LISTEN 1338/exim4
udp 0 0 0.0.0.0:38603 0.0.0.0:* 650/avahi-daemon: r
udp 0 0 0.0.0.0:5353 0.0.0.0:* 650/avahi-daemon: r
udp 0 0 0.0.0.0:53 0.0.0.0:* 721/dnsmasq
udp 0 0 0.0.0.0:67 0.0.0.0:* 1394/udhcpd
udp6 0 0 :::51837 :::* 650/avahi-daemon: r
udp6 0 0 :::5353 :::* 650/avahi-daemon: r
udp6 0 0 :::53 :::* 721/dnsmasq
iptables -I INPUT -i eth0 -p udp --sport 67:68 --dport 67:68 -j ACCEPT
/etc/dhcp# cat dhclient.conf
…
prepend domain-name-servers 127.0.0.1; # only uncommented this line
request subnet-mask, broadcast-address, time-offset, routers,
domain-name, domain-name-servers, domain-search, host-name,
dhcp6.name-servers, dhcp6.domain-search,
netbios-name-servers, netbios-scope, interface-mtu,
rfc3442-classless-static-routes, ntp-servers;
…
So what is the missing link ???
Andy