7.2.1. NAT Rules

Generally, enabling Internet access for the users requires creating at least one NAT rule from the Trusted to the Untrusted zone.

Note

The rules are applied top to bottom in their listing order. Only the first rule in which all conditions are matched is applied. This means that more specific rules must be placed higher in the list than more general ones. To change the order in which the rules will be applied, use the Up/Down and Top/Bottom buttons or drag and drop the rules with the mouse.

Note

The Negate checkbox changes the condition to the opposite, which corresponds to a Boolean NOT (negation).

To create a NAT rule, go to the Network policies --> NAT and routing section, click Add, and provide the desired settings.

Name

Description

Enabled

Enables or disables the rule.

Name

The name of the rule.

Description

A description of the rule.

Type

Select NAT.

SNAT IP address (external IP)

Explicitly sets the IP address with which the source address will be replaced in case of packet NATing. This makes sense if there are multiple IP addresses assigned to the destination zone's interfaces. If left empty, the system will use an arbitrary address from the list of available IP addresses assigned to the destination zone's interfaces. A range of IP addresses may be specified, for example:

192.168.10.10-192.168.10.20

In this case, UserGate will use all addresses from the range for Source NAT.

It is recommended to specify a SNAT IP explicitly to improve firewall performance.

Logging

Logs traffic information when the rule is triggered. The available options are:

  • Log session start: only the session start (first packet) will be recorded in the traffic log. This is the recommended logging option.

  • None. Nothing will be logged.

Source

The zone, IP address lists, or URL lists of the traffic source.

The URL list must include only domain names. Every 5 minutes UserGate resolves domain names into IP addresses and stores the result in the internal cache for the DNS record's time-to-live (TTL). When the TTL expires, UserGate automatically updates the IP address value.

Important! If MAC addresses specified, the Negate checkbox will not work.

Important! Traffic processing performed with the following statements:

  • applying logic OR if several IP lists and/or domain lists are specified;

  • applying logic AND if several GeoIP and lists of IPs and/or domains are specified.

Destination

The zone, IP address lists, or URL lists of the traffic destination.

The URL list must include only domain names. Every 5 minutes UserGate resolves domain names into IP addresses and stores the result in the internal cache for the DNS record's time-to-live (TTL). When the TTL expires, UserGate automatically updates the IP address value.

Important! Traffic processing performed with the following statements:

  • applying logic OR if several IP lists and/or domain lists are specified;

  • applying logic AND if several GeoIP and lists of IPs and/or domains are specified.

Service

The service type, such as HTTP, HTTPS or other.

Usage

The rule triggering statistics: the total number of triggers, the time of the first and last triggers.

To reset statistics, select rules in the list and click Reset hit counts.

History

The time when the rule was created and last modified, as well as the event log entries related to this rule: adding, updating the rule, changing the position of the rule in the list, etc.

Note

It is recommended to create general NAT rules, such as NAT from the local network (normally the Trusted zone) to the Internet (normally the Untrusted zone), and access restrictions by user, service, and application using firewall rules.