Configure Destination NAT with DNS Rewrite
Table of Contents
Configure Destination NAT with DNS Rewrite
Create a destination NAT policy rule for static translation
that also rewrites the IPv4 address in a DNS response based on the original
or translated destination address of the NAT rule.
When you configure a destination NAT policy
rule that performs static translation of IPv4 addresses, you can
also configure the rule so that the firewall rewrites the IPv4 address
in a DNS response based on the original or translated IP address
configured for the rule. The firewall performs NAT on the IPv4 address
(the FQDN resolution) in a DNS response (that matches the rule)
before forwarding the response to the client; thus, the client receives
the appropriate address to reach the destination service.
View
the DNS rewrite use
cases to help you determine whether to specify that the rewrite
occur in the reverse or forward direction.
You
cannot enable Bi-directional source address
translation in the same NAT rule where you enable DNS rewrite.
- Create a destination NAT policy rule that specifies the firewall perform static translation of IPv4 addresses that match the rule, and also specifies the firewall rewrite IP addresses in DNS responses when that IPv4 address (from the A Record) matches the original or translated destination address in the NAT rule.
- Select and Add a NAT policy rule.(Optional) On the General tab, enter a descriptive Name for the rule.For NAT Type, select ipv4.On the Original Packet tab, Add a Destination Address.You will also have to select a Source Zone or Any source zone, but DNS rewrite occurs at the global level; only the Destination Address on the Original Packet tab is matched. DNS Rewrite ignores all other fields on the Original Packet tab.On the Translated Packet tab, for Destination Address Translation, select Translation Type to be Static IP.Select a Translated Address or enter a new address.Enable DNS Rewrite and select a Direction:
- Select reverse (default) when the IP address in the DNS response requires the opposite translation that the NAT rule specifies. If the DNS response matches the Translated Destination Address in the rule, translate the DNS response using the reverse translation that the rule uses. For example, if the rule translates IP address 1.1.1.10 to 192.168.1.10, the firewall rewrites a DNS response of 192.168.1.10 to 1.1.1.10.
- Select forward when the IP address in the DNS response requires the same translation that the NAT rule specifies. If the DNS response matches the Original Destination Address in the rule, translate the DNS response using the same translation the rule uses. For example, if the rule translates IP address 1.1.1.10 to 192.168.1.10, the firewall rewrites a DNS response of 1.1.1.10 to 192.168.1.10.
Click OK.Commit your changes.