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Last update: 2021-10-26

Create a black hole DNAT rule

Create a black hole rule to drop packets from unwanted sources from the internet.

To create a black hole rule, do as follows:

  1. Go to Rules and policies and click NAT rules.
  2. Click Add NAT rule and then click New NAT rule.
  3. Configure the rule as follows:

    Name Description
    Rule name Enter a name.
    Original source Any
    Original destination The WAN interface of your Sophos Firewall device.
    Original service Select a service.
    Translated source (SNAT) Original
    Translated destination (DNAT) A dummy IP address (a host that does not exist).
    Translated service (PAT) Original
    Inbound interface Any
    Outbound interface Any

    Here's an example of a black hole rule:

    Example settings for a blackhole DNAT rule

  4. Click Save.

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