blacklist(5) shorewall6 Blacklist file




The blacklist file is used to perform static blacklisting by source address (IP or MAC), or by application. The use of this file is deprecated in favor of m[blue]shorewall6-blrulesm[][1](5), and beginning with Shorewall 4.5.7, the blacklist file is no longer installed. Existing blacklist files can be converted to a corresponding blrules file using the shorewall6 update -b command.

The columns in the file are as follows (where the column name is followed by a different name in parentheses, the different name is used in the alternate specification syntax).

ADDRESS/SUBNET - {-|~mac-address|ip-address|address-range|+ipset}

Host address, network address, MAC address, IP address range (if your kernel and ip6tables contain iprange match support) or ipset name prefaced by "+" (if your kernel supports ipset match). Exclusion (m[blue]shorewall6-exclusionm[][2](5)) is supported.

MAC addresses must be prefixed with "~" and use "-" as a separator.

Example: ~00-A0-C9-15-39-78

A dash ("-") in this column means that any source address will match. This is useful if you want to blacklist a particular application using entries in the PROTOCOL and PORTS columns.

PROTOCOL (proto) - {-|protocol-number|protocol-name}

Optional - if specified, must be a protocol number or a protocol name from protocols(5).

PORTS (port) - {-|port-name-or-number[,port-name-or-number]...}

May only be specified if the protocol is TCP (6), UDP (17), DCCP (33), SCTP (132) or UDPLITE (136). A comma-separated list of destination port numbers or service names from services(5).

OPTIONS - {-|{dst|src|whitelist|audit}[,...]}

Optional - added in 4.4.12. If specified, indicates whether traffic from ADDRESS/SUBNET (src) or traffic to ADDRESS/SUBNET (dst) should be blacklisted. The default is src. If the ADDRESS/SUBNET column is empty, then this column has no effect on the generated rule.

In Shorewall 4.4.12, the keywords from and to were used in place of src and dst respectively. Blacklisting was still restricted to traffic arriving on an interface that has the 'blacklist' option set. So to block traffic from your local network to an internet host, you had to specify blacklist on your internal interface in m[blue]shorewall6-interfacesm[][3] (5).

Beginning with Shorewall 4.4.13, entries are applied based on the blacklist setting in m[blue]shorewall6-zonesm[][4](5):

1. 'blacklist' in the OPTIONS or IN_OPTIONS column. Traffic from this zone is passed against the entries in this file that have the src option (specified or defaulted).

2. 'blacklist' in the OPTIONS or OUT_OPTIONS column. Traffic to this zone is passed against the entries in this file that have the dst option.

In Shorewall 4.4.20, the whitelist option was added. When whitelist is specified, packets/connections that match the entry are not matched against the remaining entries in the file.

The audit option was also added in 4.4.20 and causes packets matching the entry to be audited. The audit option may not be specified in whitelist entries and require AUDIT_TARGET support in the kernel and ip6tables.

When a packet arrives on an interface that has the blacklist option specified in m[blue]shorewall6-interfacesm[][3](5), its source IP address and MAC address is checked against this file and disposed of according to the BLACKLIST_DISPOSITION and BLACKLIST_LOGLEVEL variables in m[blue]shorewall6.confm[][5](5). If PROTOCOL or PROTOCOL and PORTS are supplied, only packets matching the protocol (and one of the ports if PORTS supplied) are blocked.


Example 1:

To block DNS queries from address fe80::2a0:ccff:fedb:31c4:

        #ADDRESS/SUBNET            PROTOCOL        PORT
        fe80::2a0:ccff:fedb:31c4/  udp             53

Example 2:

To block some of the nuisance applications:

        #ADDRESS/SUBNET         PROTOCOL        PORT
        -                       udp             1024:1033,1434
        -                       tcp             57,1433,1434,2401,2745,3127,3306,3410,4899,5554,6101,8081,9898