Manual Chapter :
Placing BIG-IP DNS in front of a Pool of DNS Servers
Applies To:
Show Versions
BIG-IP LTM
- 17.0.0, 16.1.5, 16.1.4, 16.1.2, 16.1.1, 16.1.0, 16.0.1, 16.0.0
BIG-IP DNS
- 17.0.0, 16.1.5, 16.1.4, 16.1.2, 16.1.1, 16.1.0, 16.0.1, 16.0.0
Placing BIG-IP DNS in front of a Pool of DNS Servers
Overview: Screening and forwarding non-wide IP traffic to a pool of DNS servers
BIG-IP DNS can function as a
traffic screener in front of a pool of DNS servers. In this situation, BIG-IP DNS checks
incoming DNS queries and if the query is for a wide IP, resolves the query. Otherwise,
BIG-IP DNS forwards the DNS query to one of the servers in a pool of DNS servers, and
that server handles the query.
Traffic flow when BIG-IP DNS screens traffic to a pool of DNS servers
About
listeners
A
listener
is a specialized virtual server
that passively checks for DNS packets on port 53 and the IP address you assign to the
listener. When a DNS request is sent to the IP address of the listener, the BIG-IP system
either handles the request or forwards the request to the appropriate resource. Creating a pool of local DNS servers
Ensure that at least one custom DNS monitor exists on the BIG-IP system. Gather the IP addresses of the DNS servers that you want to
include in a pool to which the BIG-IP system load balances DNS traffic.
Create a pool of local DNS servers when you want to load balance DNS queries to
other DNS servers.
- On the Main tab, click the applicable path.The Pool List screen opens.
- ClickCreate.The New Pool screen opens.
- In theNamefield, type a unique name for the pool.
- For theHealth Monitorssetting, from theAvailablelist, select the custom DNS monitor you created and move the monitor to theActivelist.
- Using theNew Memberssetting, add each resource that you want to include in the pool:
- (Optional) In theNode Namefield, type a name for the node portion of the pool member.
- In theAddressfield, type an IP address.
- In theService Portfield, type a port number, or select a service name from the list.
- (Optional) In thePriorityfield, type a priority number.
- ClickAdd.
- ClickFinished.
Creating listeners that alert BIG-IP DNS to DNS queries for a pool of DNS servers
Ensure that a pool of DNS servers exists on DNS.
Configure a listener that alerts BIG-IP DNS to DNS queries destined for a pool of DNS
servers. The best practice is to create four listeners: one with an IPv4 address that
handles UDP traffic, and one with the same IPv4 address that handles TCP traffic; one
with an IPv6 address that handles UDP traffic, and one with the same IPv6 address that
handles TCP traffic.
If you have multiple BIG-IP DNS systems in a device
group, perform this procedure on only one system.
- On the Main tab, click .The Listeners List screen opens.
- ClickCreate.The Listeners properties screen opens.
- In theNamefield, type a unique name for the listener.
- For the Destination setting, in theAddressfield, type an IPv4 address on which BIG-IP DNS listens for network traffic.
- From theListenerlist, selectAdvanced.
- For theAddress Translationsetting, select theEnabledcheck box.
- In the Service area, from theProtocollist, selectUDP.
- From theDefault Poollist, select the pool to which this listener forwards DNS queries.
- ClickFinished.
Create another listener with the same IPv4
address and configuration, but select
TCP
from the
Protocol
list. Then, create two more listeners, configuring
both with the same IPv6 address, but one with the UDP protocol and one with the TCP
protocol.
