Configure a DNS Proxy Object

Configure the basic settings for a DNS Proxy object.
Select
Network
DNS Proxy
and
Add
a new object.
Verify that
Enable
is selected.
Enter a
Name
for the object.
For
Location
, select the virtual system to which the object applies. If you select
Shared
, you must specify at least a
Primary
DNS server address, and optionally a
Secondary
address.
If you selected a virtual system, for
Server Profile
, select a DNS Server profile or else click
DNS Server Profile
to configure a new profile. See Configure a DNS Server Profile.
For Inheritance Source, select a source from which to inherit default DNS server settings. The default is
None
.
For
Interface
, click
Add
and specify the interfaces to which the DNS Proxy object applies.
If you use the DNS Proxy object for performing DNS lookups, an interface is required. The firewall will listen for DNS requests on this interface, and then proxy them.
If you use the DNS Proxy object for a service route, the interface is optional.
(
Optional
) Specify DNS Proxy rules.
On the
DNS Proxy Rules
tab,
Add
a
Name
for the rule.
Turn on caching of domains resolved by this mapping
if you want the firewall to cache the resolved domains.
For
Domain Name
,
Add
one or more domains, one entry per row, to which the firewall compares FQDN queries. If a query matches one of the domains in the rule, the query is sent to one of the following servers to be resolved (depending on what you configured in the prior step):
The
Primary
or
Secondary
DNS Server directly specified for this proxy object.
The
Primary
or
Secondary
DNS Server specified in the DNS Server profile for this proxy object.
DNS Proxy Rule and FQDN Matching describes how the firewall matches domain names in an FQDN to a DNS proxy rule. If no match is found, default DNS servers resolve the query.
Do one of the following, depending on what you set the
Location
to:
If you chose a virtual system, select a
DNS Server profile
.
If you chose
Shared
, enter a
Primary
and optionally a
Secondary
address.
Click
OK
.
(
Optional
) Supply the DNS Proxy with static FQDN-to-address entries. Static DNS entries allow the firewall to resolve the FQDN to an IP address without sending a query to the DNS server.
On the
Static Entries
tab,
Add
a
Name
.
Enter the Fully Qualified Domain Name (
FQDN
).
For
Address
,
Add
the IP address to which the FQDN should be mapped.
You can provide additional IP addresses for an entry. The firewall will provide all of the IP addresses in its DNS response and the client chooses which address to use.
Click
OK
.
Enable caching and configure other advanced settings for the DNS Proxy.
On the
Advanced
tab, select
TCP Queries
to enable DNS queries using TCP.
Max Pending Requests
—Enter the maximum number of concurrent, pending TCP DNS requests that the firewall will support (range is 64-256; default is 64).
For
UDP Queries Retries
, enter:
Interval (sec)
—The length of time (in seconds) after which another request is sent if no response has been received (range is 1 to 30; default is 2).
Attempts
—The maximum number of UDP query attempts (excluding the first attempt) after which the next DNS server is queried (range is 1 to 30; default is 5.)
Select
Cache
to enable the firewall to cache FQDN-to-address mappings that it learns. You must enable
Cache
(enabled by default) if this DNS proxy object is used for queries that the firewall generates (that is, under
Device
Setup
Services
DNS
, or under
Device
Virtual Systems
and you select a virtual system and
General
DNS Proxy
.
Select
Enable TTL
to limit the length of time the firewall caches DNS resolution entries for the proxy object. Disabled by default.
Enter
Time to Live (sec)
, the number of seconds after which all cached entries for the proxy object are removed. After the entries are removed, new DNS requests must be resolved and cached again. Range is 60-86,400. There is no default TTL; entries remain until the firewall runs out of cache memory.
Cache EDNS Responses
—You must enable this setting if this DNS proxy object is used for queries that the firewall generates (that is, under
Device
Setup
Services
DNS
, or under
Device
Virtual Systems
and you select a virtual system and
General
DNS Proxy
.
Commit your changes.
Click
OK
and
Commit
.