Manual Chapter :
Redirecting DNS Queries Using a CNAME Pool
Applies To:
Show Versions
BIG-IP LTM
- 15.1.9, 15.1.8, 15.1.7, 15.1.6, 15.1.5, 15.1.4, 15.1.3, 15.1.2, 15.1.1, 15.1.0, 15.0.1, 15.0.0, 14.1.5, 14.1.4, 14.1.3, 14.1.2, 14.1.0, 14.0.1, 14.0.0
BIG-IP DNS
- 15.1.9, 15.1.8, 15.1.7, 15.1.6, 15.1.5, 15.1.4, 15.1.3, 15.1.2, 15.1.1, 15.1.0, 15.0.1, 15.0.0, 14.1.5, 14.1.4, 14.1.3, 14.1.2, 14.1.0, 14.0.1, 14.0.0
Redirecting DNS Queries Using a CNAME Pool
Overview: Redirecting DNS queries using a CNAME pool
When you want to redirect DNS queries for a web site to a different web site, create a wide IP
that represents the original web site, and add a pool configured with a CNAME type to the wide IP
with an A record type to redirect the requests to the new destination.
The executives at
siterequest.com
recently purchased a competitor.
Site Request's administrator wants to redirect DNS queries for
competitor.com
to a rebranded web site named
competitor.siterequest.com
. About CNAME
records
A
CNAME
record specifies that a domain
name is an alias of another domain. When you create a CNAME pool with members specifying the
canonical name, BIG-IP® DNS responds to DNS name
resolution requests for A or CNAME name record type queries with these names if this pool is
added to the said wide IP.Redirecting DNS queries using a CNAME pool
Perform these tasks to redirect a DNS request using a wide IP, which includes a pool that is
configured with a CNAME type.
Creating a CNAME pool
Create a CNAME pool to which the system can load balance DNS queries. For example,
you can name the pool
competitor_redirect
and use a pool member
name of competitor.siterequest.com
. - On the Main tab, click .The Pool List screen opens.
- ClickCreate.The New Pool screen opens.
- In theNamefield, type a name for the pool.Names must begin with a letter, and can contain only letters, numbers, and the underscore (_) character.The pool name is limited to 63 characters.
- From theTypelist, select theCNAMEtype.
- In the Members area, for theMember Listsetting, from theWide IPlist, select either a pool member (A or AAAA type) or a static target, and then clickAdd.
- ClickFinished.
Creating a wide IP with a CNAME pool
Ensure that a pool configured with a CNAME type exists in the BIG-IP configuration.
Create a wide IP that includes a pool configured with a CNAME to redirect DNS
queries from a web site, to a different web site.
- On the Main tab, click .The Wide IP List screen opens.
- ClickCreate.
- In theNamefield, type a name for the wide IP.You can use two different wildcard characters in the wide IP name: asterisk (*) to represent several characters and question mark (?) to represent a single character. This reduces the number of aliases you have to add to the configuration.
- From theTypelist, select a record type to serve from the required DNS query types.If you want the BIG-IPDNS to respond to both A and CNAME record type requests, you must configure two wide IPs. One wide IP of type A with a CNAME pool type, and a second wide IP of type CNAME with a CNAME pool type. At a minimum, an A record type wide IP should be configured with a CNAME pool.
- In the Pools area, for thePool Listsetting, from thePoollist, select the name of the CNAME pool, and then clickAdd.
- ClickFinished.
Viewing statistics for wide IP CNAME resolutions
Ensure that a wide IP that includes a pool configured with a CNAME exists in the BIG-IP configuration.
You can view the number of DNS queries that BIG-IP DNS
(formerly GTM) resolved using a CNAME record.
- On the Main tab, click .The Global Traffic statistics screen opens.
- From theStatistics Typelist, selectWide IPs.Information displays about the cumulative number of DNS name resolution requests processed by the wide IP, and the number of requests load balanced using specific methods.
Implementation result
You now have an implementation in which BIG-IP®
DNS resolves a DNS query for a wide IP to a CNAME.
