Sep 14, 2018

How to configure firewall on CentOS /Oracle Linux/ Red Hat 7 and Fedora

RHEL / CentOS Oracle Linux 7 iptables was replaced with firewalld
$ sudo -i systemctl  status firewalld.service
firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled)
   Active: active (running) since Thu 2015-09-18 17:36:50 EDT; 5 days ago
 Main PID: 819 (firewalld)
   CGroup: /system.slice/firewalld.service
           └─819 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid

Sep 18 17:36:50 localhost.localdomain systemd[1]: Started firewalld - dynamic firewall daemon.


firewall-cmd is the command line client of the firewalld daemon. It provides interface to manage runtime and permanent configuration.

The runtime configuration in firewalld is separated from the permanent configuration. This means that things can get changed in the runtime or permanent configuration.

For example, to open port 80
$ sudo firewall-cmd --zone=dmz --add-port=80/tcp --permanent
Add port 4848
$ sudo -i firewall-cmd --add-port=4848/tcp --permanent
and then reload the firewall
$ sudo firewall-cmd --reload
More examples:

Use firewall-cmd to enable for example ssh:
$ sudo firewall-cmd --add-service=https
Enable samba for 10 seconds:
$ sudo firewall-cmd --add-service=samba --timeout=10
Disable mysql:
$ sudo firewall-cmd --remove-service=mysql
To restore your static firewall with lokkit again simply use:
$ sudo lokkit --enabled
$ sudo -i firewall-cmd --list-services
dhcpv6-client ssh
$ sudo -i firewall-cmd --list-ports
$ firewall-cmd --help

Usage: firewall-cmd [OPTIONS...]

General Options
  -h, --help           Prints a short help text and exists
  -V, --version        Print the version string of firewalld
  -q, --quiet          Do not print status messages

Status Options
  --state              Return and print firewalld state
  --reload             Reload firewall and keep state information
  --complete-reload    Reload firewall and loose state information

Permanent Options
  --permanent          Set an option permanently
                       Usable for options maked with [P]

Zone Options
  --get-default-zone   Print default zone for connections and interfaces
  --set-default-zone=<zone>
                       Set default zone
  --get-active-zones   Print currently active zones
  --get-zones          Print predefined zones [P]
  --get-services       Print predefined services [P]
  --get-icmptypes      Print predefined icmptypes [P]
  --get-zone-of-interface=<interface>
                       Print name of the zone the interface is bound to [P]
  --get-zone-of-source=<source>[/<mask>]
                       Print name of the zone the source[/mask] is bound to [P]
  --list-all-zones     List everything added for or enabled in all zones [P]
  --new-zone=<zone>    Add a new zone [P only]
  --delete-zone=<zone> Delete an existing zone [P only]
  --zone=<zone>        Use this zone to set or query options, else default zone
                       Usable for options maked with [Z]
  --get-target         Get the zone target [P only]
  --set-target=<target>
                       Set the zone target [P only]

IcmpType Options
  --new-icmptype=<icmptype>
                       Add a new icmptype [P only]
  --delete-icmptype=<icmptype>
                       Delete and existing icmptype [P only]

Service Options
  --new-service=<service>
                       Add a new service [P only]
  --delete-service=<service>
                       Delete and existing service [P only]

Options to Adapt and Query Zones
  --list-all           List everything added for or enabled in a zone [P] [Z]
  --list-services      List services added for a zone [P] [Z]
  --timeout=<seconds>  Enable an option for seconds only
                       Usable for options maked with [T]
  --add-service=<service>
                       Add a service for a zone [P] [Z] [T]
  --remove-service=<service>
                       Remove a service from a zone [P] [Z]
  --query-service=<service>
                       Return whether service has been added for a zone [P] [Z]
  --list-ports         List ports added for a zone [P] [Z]
  --add-port=<portid>[-<portid>]/<protocol>
                       Add the port for a zone [P] [Z] [T]
  --remove-port=<portid>[-<portid>]/<protocol>
                       Remove the port from a zone [P] [Z]
  --query-port=<portid>[-<portid>]/<protocol>
                       Return whether the port has been added for zone [P] [Z]
  --list-icmp-blocks   List Internet ICMP type blocks added for a zone [P] [Z]
  --add-icmp-block=<icmptype>
                       Add an ICMP block for a zone [P] [Z] [T]
  --remove-icmp-block=<icmptype>
                       Remove the ICMP block from a zone [P] [Z]
  --query-icmp-block=<icmptype>
                       Return whether an ICMP block has been added for a zone
                       [P] [Z]
  --list-forward-ports List IPv4 forward ports added for a zone [P] [Z]
  --add-forward-port=port=<portid>[-<portid>]:proto=<protocol>[:toport=<portid>[-<portid>]][:toaddr=<address>[/<mask>]]
                       Add the IPv4 forward port for a zone [P] [Z] [T]
  --remove-forward-port=port=<portid>[-<portid>]:proto=<protocol>[:toport=<portid>[-<portid>]][:toaddr=<address>[/<mask>]]
                       Remove the IPv4 forward port from a zone [P] [Z]


  --query-forward-port=port=<portid>[-<portid>]:proto=<protocol>[:toport=<portid>[-<portid>]][:toaddr=<address>[/<mask>]]
                       Return whether the IPv4 forward port has been added for
                       a zone [P] [Z]
  --add-masquerade     Enable IPv4 masquerade for a zone [P] [Z] [T]
  --remove-masquerade  Disable IPv4 masquerade for a zone [P] [Z]
  --query-masquerade   Return whether IPv4 masquerading has been enabled for a
                       zone [P] [Z]
  --list-rich-rules    List rich language rules added for a zone [P] [Z]
  --add-rich-rule=<rule>
                       Add rich language rule 'rule' for a zone [P] [Z] [T]
  --remove-rich-rule=<rule>
                       Remove rich language rule 'rule' from a zone [P] [Z]
  --query-rich-rule=<rule>
                       Return whether a rich language rule 'rule' has been
                       added for a zone [P] [Z]

Options to Handle Bindings of Interfaces
  --list-interfaces    List interfaces that are bound to a zone [P] [Z]
  --add-interface=<interface>
                       Bind the <interface> to a zone [P] [Z]
  --change-interface=<interface>
                       Change zone the <interface> is bound to [Z]
  --query-interface=<interface>
                       Query whether <interface> is bound to a zone [P] [Z]
  --remove-interface=<interface>
                       Remove binding of <interface> from a zone [P] [Z]

Options to Handle Bindings of Sources
  --list-sources       List sources that are bound to a zone [P] [Z]
  --add-source=<source>[/<mask>]
                       Bind <source>[/<mask>] to a zone [P] [Z]
  --change-source=<source>[/<mask>]
                       Change zone the <source>[/<mask>] is bound to [Z]
  --query-source=<source>[/<mask>]
                       Query whether <source>[/<mask>] is bound to a zone
                       [P] [Z]
  --remove-source=<source>[/<mask>]
                       Remove binding of <source>[/<mask>] from a zone [P] [Z]

Direct Options
  --direct             First option for all direct options
  --get-all-chains
                       Get all chains [P]
  --get-chains {ipv4|ipv6|eb} <table>
                       Get all chains added to the table [P]
  --add-chain {ipv4|ipv6|eb} <table> <chain>
                       Add a new chain to the table [P]
  --remove-chain {ipv4|ipv6|eb} <table> <chain>
                       Remove the chain from the table [P]
  --query-chain {ipv4|ipv6|eb} <table> <chain>
                       Return whether the chain has been added to the table [P]
  --get-all-rules
                       Get all rules [P]
  --get-rules {ipv4|ipv6|eb} <table> <chain>
                       Get all rules added to chain in table [P]
  --add-rule {ipv4|ipv6|eb} <table> <chain> <priority> <arg>...
                       Add rule to chain in table [P]
  --remove-rule {ipv4|ipv6|eb} <table> <chain> <priority> <arg>...
                       Remove rule with priority from chain in table [P]
  --remove-rules {ipv4|ipv6|eb} <table> <chain>
                       Remove rules from chain in table [P]
  --query-rule {ipv4|ipv6|eb} <table> <chain> <priority> <arg>...
                       Return whether a rule with priority has been added to
                       chain in table [P]
  --passthrough {ipv4|ipv6|eb} <arg>...
                       Pass a command through
  --get-all-passthroughs
                       Get all passthrough rules [P only]
  --get-passthroughs {ipv4|ipv6|eb} <arg>...
                       Get passthrough rules [P only]
  --add-passthrough {ipv4|ipv6|eb} <arg>...
                       Add a new passthrough rule [P only]
  --remove-passthrough {ipv4|ipv6|eb} <arg>...
                       Remove a passthrough rule [P only]
  --query-passthrough {ipv4|ipv6|eb} <arg>...
                       Return whether the passthrough rule has been added
                       [P only]

Lockdown Options
  --lockdown-on        Enable lockdown.
  --lockdown-off       Disable lockdown.
  --query-lockdown     Query whether lockdown is enabled

Lockdown Whitelist Options
  --list-lockdown-whitelist-commands
                       List all command lines that are on the whitelist [P]
  --add-lockdown-whitelist-command=<command>
                       Add the command to the whitelist [P]
  --remove-lockdown-whitelist-command=<command>
                       Remove the command from the whitelist [P]
  --query-lockdown-whitelist-command=<command>
                       Query whether the command is on the whitelist [P]
  --list-lockdown-whitelist-contexts
                       List all contexts that are on the whitelist [P]
  --add-lockdown-whitelist-context=<context>
                       Add the context context to the whitelist [P]
  --remove-lockdown-whitelist-context=<context>
                       Remove the context from the whitelist [P]
  --query-lockdown-whitelist-context=<context>
                       Query whether the context is on the whitelist [P]
  --list-lockdown-whitelist-uids
                       List all user ids that are on the whitelist [P]
  --add-lockdown-whitelist-uid=<uid>
                       Add the user id uid to the whitelist [P]
  --remove-lockdown-whitelist-uid=<uid>
                       Remove the user id uid from the whitelist [P]
  --query-lockdown-whitelist-uid=<uid>
                       Query whether the user id uid is on the whitelist [P]
  --list-lockdown-whitelist-users
                       List all user names that are on the whitelist [P]
  --add-lockdown-whitelist-user=<user>
                       Add the user name user to the whitelist [P]
  --remove-lockdown-whitelist-user=<user>
                       Remove the user name user from the whitelist [P]
  --query-lockdown-whitelist-user=<user>
                       Query whether the user name user is on the whitelist [P]

Panic Options
  --panic-on           Enable panic mode
  --panic-off          Disable panic mode
  --query-panic        Query whether panic mode is enabled