How to : Wild Card DNS

[mitto]

Ref: Linux Web admin (http://forums.linuxwebadmin.info/index.php/topic,45.0.html)

If you want to add wildcard DNS the you need to edit DNS record.There is no security It is same as you create an A record, only change is instead of record name, you need to use *


* 14400 IN A xx.xx.xx.xx

1) Enter the following line in the particular DNS zone file of the domain:


*.domain.tld IN A 1.2.3.4 ( whatever IP address of the domain.tld )

2) Enter the following line in the VirtualHost entry in the httpd.conf file for the domain:


ServerAlias *.domain.tld

Restart the httpd and named services, and also reload rndc

[Oracle]

A wildcard DNS record is a record in a DNS zone that will match requests for non-existent domain names. A wildcard DNS record is specified by using a "*" as the left most label (part) of a domain name, e.g. *.example.com. The exact rules for when a wild card will match are specified in RFC 1034, but the rules are neither intuitive nor clearly specified. This has resulted in incompatible implementations and unexpected results when they are used.

[thewebhostingdi]

In simple, anything.yourdomain.com will point to the specified IP address.

Wildcards will apply to *.yourdomain.com except for www.yourdomain.com and yourdomain.com

[HostEase]

A wildcard DNS record is a record in a DNS zone that will match requests for non-existent domain names. A wildcard DNS record is specified by using a "*" as the left most label (part) of a domain name, e.g. *.example.com. The exact rules for when a wild card will match are specified in RFC 1034, but the rules are neither intuitive nor clearly specified. This has resulted in incompatible implementations and unexpected results when they are used.
You are right.

[sajis18]

A wildcard DNS record in a zone file looks similar to this example:

*.example.com. 3600 IN MX 10 host1.example.com.

A wildcard DNS record is a record in a DNS zone that will match requests for non-existent domain names. A wildcard DNS record is specified by using a "*" as the left most label (part) of a domain name, e.g. *.example.com. The exact rules for when a wild card will match are specified in RFC 1034, but the rules are neither intuitive nor clearly specified. This has resulted in incompatible implementations and unexpected results when they are used.
Contents
[hide]

* 1 Definitions of DNS wildcards
* 2 Example wildcard usages
* 3 Wildcards in practice
* 4 Registries/ISPs that employ wildcards
* 5 Ignoring wildcards employed by others
* 6 References
* 7 External links


This wildcard DNS record will cause DNS lookups on domain names ending in example.com that do not exist to have MX records synthesized for them. So, a lookup for the MX record for somerandomname.example.com would return an MX record pointing to host1.example.com.

Wildcards in the DNS are much more limited than other wildcard characters used in other computer systems. Wildcard DNS records have a single "*" (asterisk) as the left most DNS label, such as *.example.com. Asterisks at other places in the domain will not work as a wildcard, so neither *abc.example.com nor abc.*.example.com work as wildcard DNS records. Moreover, the wild card is matched only when a domain does not exist, not just when there are no matching records of the type that has been queried for. Even the definition of "does not exist" as defined in the search algorithm of RFC 1034 section 4.3.2 can result in the wild card not matching cases that you might expect with other types of wildcards.

The original definition of how a DNS wildcard behaves is specified in RFC 1034 sections 4.3.2 and 4.3.3, but only indirectly by certain steps in a search algorithm and as a result, the rules are neither intuitive nor clearly specified. As a result, 20 years later, RFC 4592, "The Role of Wildcards in the Domain Name System" was written to help clarify the rules.

To quote RFC 1912, "A common mistake is thinking that a wildcard MX for a zone will apply to all hosts in the zone. A wildcard MX will apply only to names in the zone which aren't listed in the DNS at all." That is, if there is a wild card MX for *.example.com, and an A record (but no MX record) for www.example.com, the correct response (as per RFC 1034) to an MX request for www.example.com is "no error, but no data"; the expected response is the MX record attached to *.example.com.

[kvchosting]

* 14400 IN A IP address

[uyisdsd]

I accept with information :The exact rules for when a wild card will match are specified in RFC 1034, but the rules are neither intuitive nor clearly specified.