Cisco Cisco Prime Network Registrar 8.1 User Guide
Cisco Prime Network Registrar IPAM 8.1.1 User Guide
166 Administrators “How to” Section
The following sub-sections outline and explain the different configuration options that are
available using Cisco Prime Network Registrar IPAM with Microsoft Active Directory and
Microsoft DNS.
7.3.1 BIND DNS
Internet-standardized DNS servers have historically been based on an IETF (Internet
Internet-standardized DNS servers have historically been based on an IETF (Internet
Engineering Task Force) RFC 1034-5 (and successors) reference implementation known as
BIND (Berkeley Internet Name Domain). BIND is now supported and maintained by the
Internet Systems Consortium (ISC) and supports storage of name server and zone
configuration information in text files stored on each DNS server. BIND has been extended
significantly over the years, including a total rewrite of BIND with version 9, and provides
extensive flexibility in terms of configurability. As is often the case, with the benefit of
increasing flexibility comes increasing complexity. Cisco Prime Network Registrar IPAM
software can ease the complexity of configuring these very enabling features.
7.3.1.1
BIND Redundancy
BIND provides for redundancy using a master/slave relationship. A single master DNS server
maintains the authoritative, administrator-created and -modified copy of information for a
particular DNS domain. DNS slaves acquire their information from the master using a special
copy mechanism called a zone transfer. There are two types of zone transfers: a full transfer,
called AXFR, and a partial or incremental transfer (changed information only since the last full
transfer), called IXFR.
AXFR Zone Transfer
The single master DNS server domain information can be manually edited by an
administrator. The administrator must also update the zone serial number. When this update
is complete, the slaves detect a change in the domain’s configuration via their periodic “zone
refresh” polling of the master DNS server’s Start of Authority (SOA) record, which contains
the current serial number. Upon detecting a serial number change, the slave may then request
a full or incremental zone transfer.
Figure 7-2 AXFR Zone Transfer