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P_K's avatar
P_K
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Mar 08, 2020
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BIg-IP DNS Listener question

Hello Folks,

I'm having hard time understanding how a listener and wide IP works in the Big-IP DNS realm. Hoping to get an answer here.

 

I understand that Listener on Big-IP DNS listens and responds to DNS queries on UDP 53 and Wide-IP is the FQDN of the app that i want to load balance across Data centers.

what are the DNS changes should I make on my public DNS provider to have a query land on listener?

Should i need to create 2 listeners if i want to load balance app across 2 data centers?

 

Any help is appreciated!

 

Thanks,

PK

 

 

 

 

 

 

  • You need to delegate the zone for production.company.com from company.com

    So the zone file for company.com contains the following records:

    production.company.com NS ns1.production.company.com
    production.company.com NS ns2.production.company.com
    ns1.production.company.com A 1.1.1.1 
    ns2.production.company.com A 2.1.1.1

    So when someone queries www.production.company.com, they will send a NS query to a .com nameserver for company.com, and get a reply.

    They then send a NS query to the company.com nameserver asking for a production.company.com nameserver.

    The company.com nameserver replies that an NS record for production.company.com is at ns1.production.company.com, and to help you out, the A record for ns1.production.company.com is 1.1.1.1.

    The client then sends a www.production.company.com A record request to 1.1.1.1 which resolves the WideIP for 1.1.1.1.

    This is a standard DNS zone delegation, and your DNS provider or manager should be able to set this up without any difficulty at all.

7 Replies

  • You need to specify the IP of the listeners as the NS records for the domain that you want to return WideIPs for.

    • P_K's avatar
      P_K
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      The domain i want to use is owned by our public DNS provider and as per registrar i can only use the name server from the provider.

      For example, I want to use production.company.com and company.com is owned by a public DNS provider say ATT and so do the name servers.

  • You need to delegate the zone for production.company.com from company.com

    So the zone file for company.com contains the following records:

    production.company.com NS ns1.production.company.com
    production.company.com NS ns2.production.company.com
    ns1.production.company.com A 1.1.1.1 
    ns2.production.company.com A 2.1.1.1

    So when someone queries www.production.company.com, they will send a NS query to a .com nameserver for company.com, and get a reply.

    They then send a NS query to the company.com nameserver asking for a production.company.com nameserver.

    The company.com nameserver replies that an NS record for production.company.com is at ns1.production.company.com, and to help you out, the A record for ns1.production.company.com is 1.1.1.1.

    The client then sends a www.production.company.com A record request to 1.1.1.1 which resolves the WideIP for 1.1.1.1.

    This is a standard DNS zone delegation, and your DNS provider or manager should be able to set this up without any difficulty at all.

    • P_K's avatar
      P_K
      Icon for Altostratus rankAltostratus

      That's great explanation man!

      Just to sum it up, i have 2 data centers which means i would just use one NS IP as listener per data center. So 1.1.1.1 is listener in DC 1 and 1.1.1.2 is the listener in DC2. does that look right?