Manual Chapter : Configuring DNS64

Applies To:

Show Versions Show Versions

BIG-IP DNS

  • 14.0.1, 14.0.0

BIG-IP LTM

  • 14.0.1, 14.0.0
Manual Chapter

Configuring DNS64

Overview: Configuring DNS64

You can configure BIG-IP® Local Traffic Manager (LTM) and BIG-IP® DNS systems to handle IPv6-only client connection requests to IPv4-only servers on your network by returning an AAAA record response to the client.
When you are configuring DNS64, in addition to the BIG-IP DNS license, the system requires both CGNAT and DNS services licenses.
Mapping IPv6 addresses to IPv4 addresses
Mapping IPv6 addresses to IPv4 addresses

Creating a custom DNS profile

Before you start, make sure that you have activated licenses for BIG-IP DNS, and both the CGNAT and DNS services.
You can create a custom DNS profile to configure how the BIG-IP system handles DNS queries.
  1. On the Main tab, click
    DNS
    Delivery
    Profiles
    DNS
    or
    Local Traffic
    Profiles
    Services
    DNS
    .
    The DNS profile list screen opens.
  2. Click
    Create
    .
    The New DNS Profile screen opens.
  3. In the
    Name
    field, type a unique name for the profile.
  4. In the General Properties area, from the
    Parent Profile
    list, accept the default
    dns
    profile.
  5. Select the
    Custom
    check box.
  6. In the DNS Features area, from the
    GSLB
    list, accept the default value
    Enabled
    .
  7. In the DNS Features area, from the
    DNS IPv6 to IPv4
    list, select how you want the system to handle IPv6 to IPv4 address mapping in DNS queries and responses.
    Option
    Description
    Disabled
    The BIG-IP system does not map IPv4 addresses to IPv6 addresses.
    Immediate
    The BIG-IP system receives an AAAA query and forwards the query to a DNS server. The BIG-IP system then forwards the first good response from the DNS server to the client. If the system receives an A response first, it appends a 96-bit prefix to the record and forwards it to the client. If the system receives an AAAA response first, it simply forwards the response to the client. The system disregards the second response from the DNS server.
    Secondary
    The BIG-IP system receives an AAAA query and forwards the query to a DNS server. Only if the server fails to return a response does the BIG-IP system send an A query. If the BIG-IP system receives an A response, it appends a 96-bit user-configured prefix to the record and forwards it to the client.
    v4 Only
    The BIG-IP system receives an AAAA query, but forwards an A query to a DNS server. After receiving an A response from the server, the BIG-IP system appends a 96-bit user-configured prefix to the record and forwards it to the client.
    Select this option only if you know that all your DNS servers are IPv4 only servers.
    If you selected
    Immediate
    ,
    Secondary
    , or
    V4 Only
    two new fields display.
  8. In the DNS Features area, in the
    IPv6 to IPv4 Prefix
    field, specify the prefix the BIG-IP system appends to all A query responses to an IPv6 request.
  9. In the DNS Features area, from the
    IPv6 to IPv4 Additional Section Rewrite
    list, select an option to allow improved network efficiency for both Unicast and Multicast DNS-SD responses.
    Option
    Description
    Disabled
    The BIG-IP system does not perform additional rewrite.
    v4 Only
    The BIG-IP system accepts only A records. The system appends the 96-bit user-configured prefix to a record and returns an IPv6 response to the client.
    v6 Only
    The BIG-IP system accepts only AAAA records and returns an IPv6 response to the client.
    Any
    The BIG-IP system accepts and returns both A and AAAA records. If the DNS server returns an A record in the Additional section of a DNS message, the BIG-IP system appends the 96-bit user-configured prefix to the record and returns an IPv6 response to the client.
  10. In the DNS Features area, from the
    Use BIND Server on BIG-IP
    list, select
    Enabled
    .
    Enable this setting only when you want the system to forward non-wide IP queries to the local BIND server on BIG-IP DNS.
  11. To have the BIG-IP system set the client subnet option to the query source address for queries that do not already contain a client subnet option, from the
    Insert Source Address into Client Subnet Option
    list, select
    Enabled
    .
    This also causes the BIG-IP system to remove the client subnet option from responses to clients that did not send a client subnet option in their most recent query.
    Enabling this setting prevents the configuration of a DNS cache on the same DNS profile.
  12. Click
    Finished
    .

Assigning a DNS profile to a DNS listener

  1. On the Main tab, click
    DNS
    Delivery
    Listeners
    .
    The Listeners List screen opens.
  2. Click the name of the listener you want to modify.
  3. In the Service area, from the
    DNS Profile
    list, select the profile you created to manage IPv6 to IPv4 address mapping.
  4. Click
    Update
    .
This listener can now pass traffic between an IPv6-only client and an IPv4-only DNS server.

Assigning a DNS profile to a virtual server for IPv6 to IPv4 traffic

  1. On the Main tab, click
    Local Traffic
    Virtual Servers
    .
    The Virtual Server List screen opens.
  2. Click the name of the virtual server you want to modify.
  3. From the
    Configuration
    list, select
    Advanced
    .
  4. From the
    DNS Profile
    list, select the profile you created to manage IPv6 to IPv4 address mapping.
  5. Click
    Update
    .
This virtual server can now pass traffic between an IPv6-only client and an IPv4-only DNS server.

Implementation result

You now have an implementation of DNS64 on the BIG-IP® system.