on
Description
| Precedes an interface specification. |
Synopsis
{block | pass} {in | out} on interface [+] address_scope| interface is an interface name (NET0 or NET1). |
| The plus sign (+) is used as a wildcard to specify any character or digit in an interface name. |
| address_scope can be a unique IP or MAC address, an address space, or the keywords !, all, me, or any. |