--dumpmask=<mask>
Specify which types of packets should be added to the dumpfile. The argument should be the OR of the bitmasks for each type of packet to be dumped: it can be specified in hex by preceding the number with 0x in the normal way. Each time a packet is written to the dumpfile, dnsmasq logs the packet sequence and the mask
representing its type. The current types are: 0x0001 - DNS queries from clients, 0x0002 DNS replies to clients, 0x0004 - DNS queries to upstream, 0x0008 - DNS replies from upstream, 0x0010 - queries send upstream for DNSSEC validation, 0x0020 - replies to queries for DNSSEC validation, 0x0040 - replies to client queries which fail DNSSEC validation, 0x0080 replies to queries for DNSSEC validation which fail validation, 0x1000 - DHCPv4, 0x2000 - DHCPv6, 0x4000 - Router advertisement, 0x8000 - TFTP.