Nortel Networks WEB OS 212777 - Manual (Page 390)

Web OS 10.0 Application Guide
390 n Chapter 15: Content Intelligent Switching
212777-A, February 2002
DNS Load Balancing
The Internet name registry has become so large that a single server cannot keep track of all the
entries. This is resolved by splitting the registry and saving it on different servers.
If you have large DNS server farms, Web OS allows you to load balance traffic based on DNS
names. To load balance DNS names, the host name is extracted from the query, processed by
the regular expressions engine, and the request is sent to the appropriate real server.
For example, Figure 15-4 shows a DNS server farm load balancing DNS queries based on
DNS names. Requests with DNS names beginning with A through G are sent to Server 1; DNS
names beginning with H through M are sent to Server 2; DNS names beginning with N through
T are sent to Server 3; DNS names beginning with U through Z are sent to Server 4.
Figure 15-4 Load Balancing DNS Queries
Client
Web Switch
DNS Server Farm
DNS Queries A - G
DNS Queries H - M
DNS Queries N - T
Server 1
Server 2
Server 3
DNS Queries U - Z
Server 4