Manual Chapter : Creating virtual servers to process DNS queries

Applies To:

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BIG-IP DNS

  • 14.0.1, 14.0.0

BIG-IP LTM

  • 14.0.1, 14.0.0
Manual Chapter

Creating virtual servers to process DNS queries

Create virtual servers to process the DNS queries that DNS Express handles. When DNS Express is only answering DNS queries, only two virtual servers are required: one with an IPv4 address that handles UDP traffic and one with an IPv6 address that handles UDP traffic.
However, the best practice is to create four listeners, which allows DNS Express to handle zone transfers, should you decide to use this feature. DNS zone transfers use TCP port
53
. With this configuration, you create one virtual server with an IPv4 address that handles UDP traffic, and one with the same IPv4 address that handles TCP traffic. You also create one virtual server with an IPv6 address that handles UDP traffic, and one with the same IPv6 address that handles TCP traffic.
These steps apply only to LTM-provisioned systems.
  1. On the Main tab, click
    Local Traffic
    Virtual Servers
    .
    The Virtual Server List screen opens.
  2. Click the
    Create
    button.
    The New Virtual Server screen opens.
  3. In the
    Name
    field, type a unique name for the virtual server.
  4. In the
    Destination Address/Mask
    field, type the IP address in CIDR format.
    The supported format is address/prefix, where the prefix length is in bits. For example, an IPv4 address/prefix is
    10.0.0.1
    or
    10.0.0.0/24
    , and an IPv6 address/prefix is
    ffe1::0020/64
    or
    2001:ed8:77b5:2:10:10:100:42/64
    . When you use an IPv4 address without specifying a prefix, the BIG-IP system automatically uses a
    /32
    prefix.
    The IP address for this field needs to be on the same subnet as the external self-IP.
  5. In the
    Service Port
    field, type
    53
    .
  6. From the
    Protocol
    list, select
    UDP
    .
  7. Optional: If you are using SNATs on your network, from the
    Source Address Translation
    list, select
    SNAT
    .
  8. Optional: From the
    SNAT pool
    list, select the name of an existing SNAT pool.
  9. From the
    Configuration
    list, select
    Advanced
    .
  10. From the
    DNS Profile
    list, select either
    dns
    or the custom DNS profile you created for DNS Express.
  11. Click
    Finished
    .
Create another virtual server with the same IPv4 address and configuration, but select
TCP
from the
Protocol
list. Then, create two more virtual servers, configuring both with the same IPv6 address, but one with the UDP protocol and one with the TCP protocol.