On 14/04/2020 18:51, Josh H wrote: > Hi there, > > I'm receiving no DHCPOffer back from my DHCPDiscover. However, I can > tcpdump the machine running dnsmasq and it is receiving the DHCPOffer > packets. > > Here's my very very simple dnsmasq.conf > # To disable dnsmasq's DNS server functionality. > port=0 > > # To enable dnsmasq's DHCP server functionality. > dhcp-range=192.168.1.3,192.168.1.8,255.255.255.240,12h > > # Set gateway as Router. Following two lines are identical. > #dhcp-option=option:router,192.168.0.1 > dhcp-option=3,192.168.0.1 > > # Set DNS server as Router. > dhcp-option=6,192.168.0.1 > > # Logging. > log-facility=/var/log/dnsmasq.log # logfile path. > log-async > log-queries # log queries. > log-dhcp # log dhcp related messages. > > Here's the contents of /var/log/dnsmasq.log after running dhclient on a > machine connected to the subnet: > Apr 14 18:36:57 dnsmasq[1702]: started, version 2.80 DNS disabled > Apr 14 18:36:57 dnsmasq[1702]: compile time options: IPv6 GNU-getopt > DBus i18n IDN DHCP DHCPv6 no-Lua TFTP conntrack ipset auth DNSSEC > loop-detect inotify dumpfile > Apr 14 18:36:57 dnsmasq-dhcp[1702]: DHCP, IP range 192.168.1.3 -- > 192.168.1.8, lease time 12h >
So, nothing logged indicating that the DHCPDiscover has been recieved? If not, my guess would be an iptables rules blocking incoming packets sent to 255.255.255.255. > I can see the service running with netstat -anp4: > Active Internet connections (servers and established) > Proto Recv-Q Send-Q Local Address Foreign Address > State PID/Program name > udp 0 0 0.0.0.0:67 <http://0.0.0.0:67/> > 0.0.0.0:* 1702/dnsmasq > udp 0 0 0.0.0.0:1701 <http://0.0.0.0:1701/> > 0.0.0.0:* 1607/xl2tpd > > There are no firewalls setup anywhere on my network for the moment. I > have been able to get isc-dhcp-server to successfully allocate DHCP > requests just fine however, so I don't think it's anything broken with > DHCP in general. I'm running Linux kernel 5.6.2 and using dnsmasq from > Debian Bullseye. Working on ISC but not dnsmasq reinforces my diagnosis: dhcpd bypasses iptables for such packets, dnsmasq doesn't. Cheers, Simon. > > Hopefully someone can work out my issue! > Thank you very much! > > _______________________________________________ > Dnsmasq-discuss mailing list > [email protected] > http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss > _______________________________________________ Dnsmasq-discuss mailing list [email protected] http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
