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ACL Violation when attempting WAN to LAN NAT v19.5.0


I have searched and can see others have this issue, however none of the solutions have worked for me so far.

I have followed the steps at https://docs.sophos.com/nsg/sophos-firewall/19.5/Help/en-us/webhelp/onlinehelp/AdministratorHelp/RulesAndPolicies/NATRules/RulesPoliciesCreateDNATAndFirewallRulesForInternalServers/index.html#specify-the-nat-rule-settings to create the following policies, with the intention of allowing WAN -> LAN traffic the specified ports:

NAT Rule:

Sophos Public Address is an IP

Valheim Server is an IP

Firewall Rule:

The service 'Valheim' is defined as:

The packet captures I have been getting are as follows:

(apologies for drop-packet as an image and not plain text)

Any help would be greatly appreciated

Edited TAGs
[edited by: emmosophos at 6:18 PM (GMT -8) on 6 Feb 2023]