Prime Network Registrar

Cisco Prime Network Registrar is a high-performance, scalable, integrated DNS and DHCP solution that enables end to end IPv4 and IPv6 networks and allows dual-stack deployments on a single server. The solution includes the following integrated components and their respective services, all of which support both IPv4 and IPv6:

  • A single DHCP server for device network access

  • A single DNS server for IP address translation and service delivery

  • A DNS caching server that supports DNS Security Extensions (DNSSEC) and is designed to prevent cache poisoning and other attacks


Why CPNR Stands Out


One CPNR instance can handle:

  • Over 100,000 leases per second for DHCPv4 and DHCPv6.
  • Over 150,000 queries per second for DNS


Discriminating Rate Limiter (DRL) ensure avalanche protection and all incoming requests are handled gracefully without affecting server performance.


One instance of CPNR can support over 4 Million IP Addresses or 6 Million Resource Records.



You can write extensions to affect how Cisco Prime Network Registrar handles and responds to DHCP requests, and to change the behavior of a DHCP server that you cannot normally do using the user interfaces. This chapter describes the extension points to which you can attach extensions for DHCPv4 and DHCPv6. Extensions can be written in TCL or C/C++ and are supported on all Network Registrar supported operating platforms.

Choosing Extension Languages

You can write extensions in Tcl or C/C++. The capabilities of each language, so far as the DHCP server is concerned, are similar, although the application programming interface (API) is slightly different to support the two very different approaches to language design:

Tcl - Although scripting in Tcl might be somewhat easier than scripting in C/C++, it is interpreted and single-threaded, and might require more resources. However, you might be less likely than in C/C++ to introduce a serious bug, and there are fewer chances of a server failure. Cisco Prime Network Registrar currently supports Tcl version 8.4.

C/C++— - This language provides the maximum possible performance and flexibility, including communicating with external processes. However, the C/C++ API is more complex than the Tcl API. Also, the possibility of a bug in the extension causing a server failure is also more likely in C/C++.


Typical Deployment of CPNR