Network interface name. You have to use network configuration key names for VMs and containers ('net\d+'). Host related rules can use arbitrary strings.
+`--log` `<alert | crit | debug | emerg | err | info | nolog | notice | warning>` ::
+
+Log level for firewall rule.
+
`--proto` `<string>` ::
IP protocol. You can use protocol names ('tcp'/'udp') or simple numbers, as defined in '/etc/protocols'.