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Setting Up Access Control Lists (ACL)Locate this document in the navigation structure


You can set up an ACL (“access control list”) and use it to control which connections the gateway accepts and which it does not. They are based on the IP addresses of the clients. The same ACL file is used for the “standard” and for the “SNC” gateway port.

  1. Create an ACL file using the syntax described below.

  2. In the instance profile of the gateway instance you set parameter gw/acl_file to the file path of the ACL file.


    If this parameter is not set, the gateway accepts all connection requests.

Syntax of the ACL File

Lines in the ACL must have the following syntax:

<permit | deny> <ip-address[/mask]> [tracelevel] [# comment]


  • permit = permits a connection, and deny = denies a connection.

  • <ip address> : The IP address must be an IPv4 or IPv6 address in the following form:

    • IPv4: 4 byte, decimal, '.' separated: e.g.

    • IPv6: 16 byte, hexadecimal, ':' separated. '::' is supported

  • <mask> : If a mask is specified, it must be a subnetwork prefix mask:

    • IPv4: 0-32

    • IPv6: 0-128

  • <trace level> : Trace level, with which ACL hits (matches of addresses based on the subnetwork mask) are written to the relevant trace file (default value 2).

  • <# comment> : Comment lines begin with a hash sign ( # ).

  • The file can contain blank lines.

  • As the last rule a general ban is inserted automatically.

To make it obvious, an explicit deny should be entered anyway as the last rule. The rules are checked sequentially from the “top down” . The first relevant rule determines the result ( “first match” ).


permit         # permit client network

permit      # permit server network

permit 1        # screening rule

                           # (learning mode, trace-level 1)

permit 2001:db8::1428:57ab # permit IPv6 host

deny           # deny the rest

More Information

For more information about the parameters, see Security Parameters.