DNRD is a proxy DNS daemon. It supports several forward servers for redundancy and/or load-balancing. DNS queries for specific domains can be forwarded to a specific group of DNS servers (with redundancy and load balancing) for that domain. It is very useful in VPN and dialup environments but can also be used as a DNS cache or ad-blocker for networks and workstations.
Dnsmasq is a lightweight, easy to configure DNS forwarder and DHCP server. It is designed to provide DNS and (optionally) DHCP to a small network. It can serve the names of local machines which are not in the global DNS. The DHCP server integrates with the DNS server and allows machines with DHCP-allocated addresses to appear in the DNS with names configured either in each host or in a central configuration file. Dnsmasq supports static and dynamic DHCP leases and BOOTP/TFTP for network booting of diskless machines.
SendIP is a command-line tool to send arbitrary IP packets. It has a large number of options to specify the content of every header of a RIP, RIPng, BGP, TCP, UDP, ICMP, or raw IPv4/IPv6 packet. It also allows any data to be added to the packet. Checksums can be calculated automatically, but if you wish to send out wrong checksums, that is supported too.
UpdateDD is a command line tool that updates a dynamic DNS record. It supports the following features: Web-based IP-detection, IP address caching, configuration files with C-like syntax, simple interface for managing multiple accounts and hostnames, and status output to syslog. Supported services include: changeip.com, dyndns.org, eurodyndns.org, ovh.net, no-ip.org, ods.org, hn.org, regfish.com, and tzo.com.
NicTool is a DNS management suite with support for various DNS servers (djbdns, BIND, PowerDNS), SQL data storage, DNS entry parsing (RFC 1034 & 1035 compliance), tiered and delegated permissions so you can safely grant access to clients and admins, giving them only the permissions they need. Humans interact via the Web interface, and an API is used for scripting mass updates, DNS templates, provisioning, and more. All changes are logged to easily track change history and see who changed what, and when.
OpenDD is a DynDNS client, written in C, and especially designed for small gateway machines, like a Soekris box. Its main feature is that it does not require any Perl or Python interpreter. It supports HTTPS, can send a mail report, and can run as daemon. It is also very easy to deploy.
adsuck is a small DNS server that spoofs blacklisted addresses and forwards all other queries. The idea is to be able to prevent connections to undesirable sites such as ad servers, crawlers, etc. It can be used locally, for the road warrior, or on the network perimeter in order to protect local machines from malicious sites.