Dnsmasq DNS DHCP Server

Dnsmasq is a lightweight, easy-to-configure DNS forwarder and DHCP server designed for small networks, providing local DNS caching, DHCP address allocation, and network boot support in a single compact binary. Developed by Simon Kelley since 2002, Dnsmasq is included in most Linux distributions and used in home routers, enterprise gateways, and OpenWrt. Key features include: DNS forwarding (caches DNS responses to reduce upstream queries and improve lookup speed, with configurable upstream server specification per-domain), DHCP server (dynamic IP address assignment with MAC-to-IP binding, DHCP option configuration including default gateway, DNS server, NTP server, and domain name), DHCPv6 and RA (stateless and stateful DHCPv6 address assignment with Router Advertisement for IPv6 autoconfiguration), PXE boot support (network boot configuration for PXE clients with custom boot filenames and next-server specification), TFTP server (built-in read-only TFTP server for serving boot images to network-bootable clients), DNSSEC validation (cryptographic validation of DNS responses using DNSSEC with automatic trust anchor management), DNS rebinding protection (blocks private IP addresses in DNS responses from upstream servers to prevent DNS rebinding attacks), local DNS (serve local hostnames from /etc/hosts file and automatically register DHCP leases as local DNS entries), domain matching (conditional forwarding of DNS queries for specific domains to designated upstream servers), tags and DHCP options (per-tag DHCP option configuration enabling different settings for wired, wireless, and VoIP clients), and configuration (command-line flags and configuration file with include directive for modular configuration).