how to (blacklist) allow a client to make resolutions only for a specific domain

[#1]

HI guys,

how to allow a client to make resolutions only for a specific domain e.g: * .webex.com ?

we have syntax errors.

e.g:

header-blacklistrule,parent*,domain_name*,action*

BlacklistRule,WebEx,*.webex.com,PASS-----> syntaxe errors

BlacklistRule,WebEx,.webex.com,PASS-----> syntaxe errors

BlacklistRule,WebEx,webex.com,PASS ----> OK for only webex.com but  not the subdomain (e.g: www.webex.com)

BlacklistRule,WebEx,google.com,REDIRECT------> OK

BlacklistRule,WebEx,*.eu,REDIRECT-----> syntaxe errors

Could you tell us what is the syntax in a blacklist to allow a domain and the entire sub Domain of it?

Regards

[#2]

can you explain why is this difference for www.webex.com and webex.com

This an example of my nslookup in lab using the blacklist.

header-blacklistrule,parent*,domain_name*,action*
BlacklistRule,WebEx,webex.com,PASS
BlacklistRule,WebEx,google.com,REDIRECT

> server 1.2.3.4
Default Server: [1.2.3.4]
Address: 1.2.3.4
> google.com
Server: [1.2.3.4]
Address: 1.2.3.4
*** [1.2.3.4] can't find google.com: Query refused
> www.google.com
Server: [1.2.3.4]
Address: 1.2.3.4
*** [1.2.3.4] can't find www.google.com Query refused

> webex.com
Server: [1.2.3.4]
Address: 1.2.3.4

Non-authoritative answer:
Name: webex.com
Address: 51.2.3.5
> www.webex.com
Server: [1.2.3.4]
Address: 1.2.3.4
*** [1.2.3.4] can't find www.webex.com Query refused
>

As you can see for www.webex.com I have Query refused
And for webex.com it's ok.

[#3 · Accepted solution]

the answer:

Webex.com is a zone. Inside which www is a record.

In simple terms the dns service provider will be only aware of WebEx.com detail.

But when they receive a query for www.webex.com, they will inform you that WebEx.com is accountable for that and your dns server will then connect WebEx.com for record response of www.webex.com.