Glossary
3-DNS® Administrator Guide Glossary-9
root name server
A root name server is a master DNS server that maintains a complete DNS
database. There are approximately 13 root name servers in the world that
manage the DNS database for the World Wide Web.
Round Robin mode
Round Robin mode is a static load balancing mode that bases connection
distribution on a set server order. Round Robin mode sends a connection
request to the next available server in the order.
Round Trip Time mode
Round Trip Time mode is a dynamic load balancing mode that bases
connection distribution on which virtual server has the fastest measured
round trip time between the data center server and the local DNS server.
RTT (round trip time)
RTT is the calculation of the time (in microseconds) that a local DNS server
takes to respond to a ping issued by the big3d agent running on a data center
server. The 3-DNS Controller takes RTT values into account when it uses
dynamic load balancing modes.
secondary DNS
The secondary DNS is a name server that retrieves DNS data from the name
server that is authoritative for the DNS zone.
Setup utility
The Setup utility is a utility that takes you through the initial system
configuration process. The Setup utility runs automatically when you turn
on a 3-DNS Controller for the first time.
site content
Site content is data (including text, images, audio, and video feeds) that is
accessible to clients who connect to a given site. See also dynamic site
content, static site content.
SNMP (Simple Network Management Protocol)
SNMP is the Internet standard protocol, defined in STD 15, RFC 1157, that
was developed to manage nodes on an IP network.
sod (switch over daemon)
The sod daemon controls the fail-over process in a redundant system.
SSH
SSH is a protocol for secure remote login and other secure network services
over a non-secure network.