Shows the possible configurations you can use for Prisma
Access to resolve DNS queries for mobile users and remote networks.
| Where Can I Use
This? | What Do I Need? |
|---|
Prisma Access allows you to specify DNS servers to resolve
both domains that are internal to your organization and external
domains. Prisma Access proxies the DNS request based on the configuration
of your DNS servers. The following table shows the supported DNS
resolution methods for internal and external domains and indicates
when Prisma Access proxies the DNS requests.
| Internal DNS Resolution Method | External DNS Resolution Method | Prisma Access Proxies the DNS Request (Yes/No) |
|---|
| Single rule, DNS server configured for Internal
Domains | Cloud Default (Google Public DNS64 for
IPv6) | Yes |
| Single rule, DNS server configured for Internal
Domains | Same as Internal Domains | No |
| Single rule, DNS server configured for Internal
Domains | Custom DNS server (Google Public DNS64 for
IPv6) | Yes |
| Single rule, Cloud Default set for a domain | Cloud Default (Google Public DNS64 for
IPv6) | Yes |
| Single rule, Cloud Default set for a domain | Same as Internal Domains (Google Public DNS64 for
IPv6) | Yes |
| Single rule, Cloud Default set for domain | Custom DNS server (Google Public DNS64 for
IPv6) | Yes |
| Multiple rules, DNS server configured for Internal
Domains | Cloud Default (Google Public DNS64 for
IPv6) | Yes |
| Multiple rules, DNS server configured for Internal
Domains | Same as Internal Domains | Yes |
| Multiple rules, DNS server configured for Internal
Domains | Custom DNS server (Google Public DNS64 for
IPv6) | Yes |
| No configuration | Custom DNS Server (Google Public DNS64 for
IPv6) | Yes |
| No configuration | Cloud Default (For IPv6, Primary = Google Public
DNS64, Secondary = Cloud Default) | No |
| No configuration | No configuration | No |
| No DNS resolution specified (default configuration
is present, which uses Cloud Default) | No DNS resolution specified | No |
| ZTNA Connector (regardless of DNS resolution
method) | N/A | Yes |
|
The source IP address of the DNS request depends
on whether or not Prisma Access proxies the DNS request.
When
Prisma Access does not proxy the DNS requests, the source IP address
of the DNS request changes to the IP address of the device that
requested the DNS lookup. This source IP address allows you to enforce
source IP address-based DNS policies or identify endpoints that
communicate with malicious domains. This behavior applies for both mobile
users and remote network deployments.
When Prisma Access proxies the DNS requests, the source IP
address of the DNS request changes to the following addresses:
Mobile User deployments—The source IP address of the DNS request is an IP address taken
from the
mobile user IP address
pool for internal requests and the mobile user location’s
gateway IP address for external requests.
Remote Network deployments—The source IP address of the DNS request is the
EBGP
Router Address for internal requests and the
Service IP
Address
of the remote network connection for
external requests.
The
following guidelines and restrictions apply to using DNS resolution
with Prisma Access:
The maximum number of concurrent
pending TCP DNS requests ( Max Pending Requests)
that Prisma Access supports is 64.
For UDP queries, the DNS proxy sends another request if it
hasn’t received a response in 2 seconds, and retries a maximum of
5 times before trying the next DNS server.
Prisma Access caches the DNS entries with a time-to-live
(TTL) value of 300 seconds. EDNS responses are also cached.
