Forum Discussion

P_K's avatar
P_K
Icon for Altostratus rankAltostratus
Mar 08, 2020

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

 

 

 

 

 

 

  • Simon_Blakely's avatar
    Simon_Blakely
    Mar 10, 2020

    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.

  • Simon_Blakely's avatar
    Simon_Blakely
    Icon for Employee rankEmployee
    Mar 10, 2020

    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
      Icon for Altostratus rankAltostratus
      Mar 10, 2020

      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.

  • Simon_Blakely's avatar
    Simon_Blakely
    Icon for Employee rankEmployee
    Mar 10, 2020

    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
      Mar 10, 2020

      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?