PHREL is a per host rate limiter. It will track the rate of incoming traffic on a server and insert a chain into iptables when a configured threshold is crossed. The inserted chain may either rate limit or block the offending host for a period of time. The inserted chain is automatically removed when the offending host's traffic levels return to normal. PHREL is particularly well suited to protecting nameservers (DNS) from random hosts that flood requests, and to preventing SSH brute force login attempts.
Avahi is a framework for Multicast DNS Service Discovery (mDNS/DNS-SD a.k.a. Zeroconf) on Linux. It allows programs to publish and discover services running on a local network with no specific configuration. For example, you can plug into a network and instantly find printers to print to, files to look at, and people to talk to.
ldap2dns is a program to read DNS (Domain Name Service) records from an LDAP directory and format them into flat files suitable for TinyDNS (or Bind). ldap2dns reduces all kinds of administration overhead: no more flat file editing, no more zone file editing. After having installed ldap2dns, the administrator only has to modify the data stored in the LDAP directory. Access control can be configured for each zone, GUIs can be more easily implemented, and all other kinds of zone and resource record information can be managed without interfering with the DNS server directly.
dns.c is a recursive, re-entrant, non-blocking DNS resolver in a single .c file. It features a record-agnostic API, restartable record iterators, and smart queries which recursively follow out-of-bailiwick NS, MX, and SRV host references. It works just as well as a stub resolver, too. It also includes spf.c, a non-blocking SPF resolver with no threading, no forking, and no run-time dependencies.
The CMU NetReg package is a scalable and flexible Web-based system for managing networks. It consolidates information about DNS zones, subnets, machine registrations, and DHCP configuration, and provides tools for easy management. The system exports ISC BIND configuration and zones, and can update them via either static zone files or TSIG signed dynamic DNS updates. It also exports ISC DHCP configurations, and has a SOAP API for integration with other systems.