SHOREWALL-ARPRULES(5)

NAME
arprules - Shorewall ARP rules file

SYNOPSIS

/etc/shorewall/arprules

DESCRIPTION

IPv4 only.

This file was added in Shorewall 4.5.12 and is used to describe low-level rules managed by arptables (8). These rules only affect Address Resolution Protocol (ARP), Reverse Address Resolution Protocol (RARP) and Dynamic Reverse Address Resolution Protocol (DRARP) frames.

The columns in the file are as shown below. MAC addresses are specified normally (6 hexadecimal numbers separated by colons).

ACTION
    Describes the action to take when a frame matches the criteria in the other columns. Possible values are:

    ACCEPT
        This is the default action if no rules matches a frame; it lets the frame go through.

    DROP
        Causes the frame to be dropped.

    SNAT:ip-address
        Modifies the source IP address to the specified ip-address.

    DNAT:ip-address
        Modifies the destination IP address to the specified ip-address.

    SMAT:mac-address
        Modifies the source MAC address to the specified mac-address.

    DMAT:mac-address
        Modifies the destination MAC address to the specified mac-address.

    SNATC:ip-address
        Like SNAT except that the frame is then passed to the next rule.

    DNATC:ip-address
        Like DNAT except that the frame is then passed to the next rule.

    SMATC:mac-address
        Like SMAT except that the frame is then passed to the next rule.

    DMATC:mac-address
        Like DMAT except that the frame is then passed to the next rule.

SOURCE - [interface[:[!]ipaddress[/ipmask][:[!]macaddress[/macmask]]]]
    Where

    interface
        Is an interface defined in shorewall-interfaces(5).

    ipaddress
        is an IPv4 address. DNS names are not allowed.

    ipmask
        specifies a mask to be applied to ipaddress.

    macaddress
        The source MAC address.

    macmask
        Mask for MAC address; must be specified as 6 hexadecimal numbers separated by colons.

    When '!' is specified, the test is inverted.

    If not specified, matches only frames originating on the firewall itself.

        Caution
        Either SOURCE or DEST must be specified.

DEST - [interface[:[!]ipaddress[/ipmask][:[!]macaddress[/macmask]]]]
    Where

    interface
        Is an interface defined in shorewall-interfaces(5).

    ipaddress
        is an IPv4 address. DNS Names are not allowed.

    ipmask
        specifies a mask to be applied to frame addresses.

    macaddress
        The destination MAC address.

    macmask
        Mask for MAC address; must be specified as 6 hexadecimal numbers separated by colons.

    When '!' is specified, the test is inverted and the rule matches frames which do not match the specified address/mask.

    If not specified, matches only frames originating on the firewall itself.

    If both SOURCE and DEST are specified, then both interfaces must be bridge ports on the same bridge.

        Caution
        Either SOURCE or DEST must be specified.

OPCODE - [[!]opcode]
    Optional. Describes the type of frame. Possible opcode values are:

    1
        ARP Request

    2
        ARP Reply

    3
        RARP Request

    4
        RARP Reply

    5
        Dynamic RARP Request

    6
        Dynamic RARP Reply

    7
        Dynamic RARP Error

    8
        InARP Request

    9
        ARP NAK

    When '!' is specified, the test is inverted and the rule matches frames which do not match the specified opcode.

EXAMPLE

The eth1 interface has both a public IP address and a private address (10.1.10.11/24). When sending ARP requests to 10.1.10.0/24, use the private address as the IP source:

    #ACTION                SOURCE                  DEST                ARP OPCODE
    SNAT:10.1.10.11        -                       eth1:10.1.10.0/24   1

FILES

/etc/shorewall/arprules

SEE ALSO

shorewall(8)