Proxy for dns server – Brocade Virtual ADX Global Server Load Balancing Guide (Supporting ADX v03.1.00) User Manual

Page 27

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Brocade Virtual ADX Global Server Load Balancing Guide

53-1003245-01

Proxy for DNS server

•

If a site contains ADX devices, identify the ADX devices within the server sites. This initiates the
Brocade GSLB protocol between the ADX device acting as a DNS proxy and the remote ADX
devices in the GSLB sites. The DNS proxy uses information supplied by the remote ADX devices
to assess the preferability of IP addresses in the DNS replies.

NOTE

You can use the GSLB Brocade Virtual ADX for standard SLB. In this case, identify the local site
and the GSLB Brocade Virtual ADX in the same way as you identify the other sites and ADX
devices. The configuration steps are the same.

•

Identify the DNS zones and the hosts within those zones for which you want the GSLB Brocade
Virtual ADX to perform GSLB. You must specify the zones and hosts. There are no defaults.

•

Identify the host applications with each host. The GSLB Brocade Virtual ADX performs GSLB for
the applications you specify. You can specify applications known to the Brocade Virtual ADX as
well as the TCP or UDP port numbers of applications that are not known to the Brocade Virtual
ADX. The Brocade Virtual ADX performs Layer 7 and Layer 4 health checks for the applications
known to the Brocade Virtual ADX, but performs only Layer 4 health checks for applications
that are not know to it. Refer to

“Server health”

on page 7.

Proxy for DNS server

Since the Brocade Virtual ADX runs router code, all you need to configure the GSLB ADX as a proxy
for a DNS server is an interface IP and an IP route on the ADX that can reach the DNS server.

Then, complete the following steps.

1. Add a real server for the DNS server.

2. Add a virtual server for the DNS server and bind the real DNS server and virtual server

together.

NOTE

As an alternative to configuring the GSLB Brocade Virtual ADX as a proxy, you can configure it to
intercept and either redirect or directly respond to DNS queries. Refer to

“DNS cache proxy”

page 65 and

“Transparent DNS query intercept”

on page 69.

Configuring real server and virtual server for the DNS server

NOTE

The virtual server IP address (VIP) will be the Authoritative DNS server for the GSLB Domain.

To configure a real server and virtual server and bind them together for a proxy DNS server, enter
commands such as the following.

Virtual ADX(config)#server real-name dns_ns 10.157.23.46

Virtual ADX(config-rs-dns_ns)#port dns proxy

Virtual ADX(config-rs-dns_ns)#exit

Virtual ADX(config)#server virtual-name-or-ip dns-proxy 10.157.23.87