firewalld 를 이용해서 방화벽을 구성해 보자.

• RedHat, Ubuntu, OpenSUSE LEAP 15.0 등은 시스템 기본 파이어월 관리자로 firewalld 를 제공한다고 한다.

firewalld

firewalld 는 ….

firewalld는 ufw 처럼 iptables 을 구성할 수 있다.

네트워크를 지역 관리가 가능해서 다른 네트워크, 지역에 따라 다른 규칙으로 구성해서 사용할 수 있다.
For example “Home” and “Office” where all communications with local machines are allowed, and “Public Wi-Fi” where no communication with the same subnet would be allowed.

https://www.ctrl.blog/entry/ufw-vs-firewalld

firewalld 설치

OpenSUSE LEAP 15.0, RedHat, Ubuntu 등은 시스템 기본 파이어월 관리자로 firewalld 를 제공한다고 한다.

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$ sudo apt install firewalld

Start firewalld

To start firewalld, enter the following command as root:

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systemctl start firewalld

root 사용자로 시작한다.

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sudo systemctl enable firewalld
sudo reboot

For more information about the service status, use the systemctl status sub-command:

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sudo systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: disabled)
   Active: active (running) since Thu 1970-01-01 09:01:48 KST; 48 years 6 months ago

sudo firewall-cmd --state

Stop firewalld

To stop firewalld, enter the following command as root:

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systemctl stop firewalld

To prevent firewalld from starting automatically at system start, enter the following command as root:

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systemctl disable firewalld

To make sure firewalld is not started by accessing the firewalld D-Bus interface and also if other services require firewalld, enter the following command as root:

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systemctl mask firewalld

사용해 보기

firewalld 는 명령라인 firewall-cmd 와 GUI로 firewall-config 명령을 지원한다.

Zone 설정

Get a list of all supported zones

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firewall-cmd --get-zones

List all zones with the enabled features.

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$ firewall-cmd --list-all-zones
...

public
  target: default
  icmp-block-inversion: no
  interfaces:
  sources:
  services: ssh dhcpv6-client http https
  ports:
  protocols:
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:

기본으로 제공하는 Zone

• drop: Any incoming network packets are dropped, there is no reply. Only outgoing network connections are possible.
• block: Any incoming network connections are rejected with an icmp-host-prohibited message for IPv4 and icmp6-adm-prohibited for IPv6. Only network connections initiated within this system are possible.
• public: For use in public areas. You do not trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.
• external: For use on external networks with masquerading enabled especially for routers. You do not trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.
• dmz: For computers in your demilitarized zone that are publicly-accessible with limited access to your internal network. Only selected incoming connections are accepted.
• work
  For use in work areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.
• home
  For use in home areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.
• internal
  For use on internal networks. You mostly trust the other computers on the networks to not harm your computer. Only selected incoming connections are accepted.
• trusted
  All network connections are accepted.

Zone

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sudo firewall-cmd --get-default-zone
public

서비스

This command prints a space separated list.

Get a list of all supported services

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$ firewall-cmd --get-services

This command prints a space separated list.

Get a list of all supported icmptypes

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firewall-cmd --get-icmptypes

서비스를 제거하려면

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# firewall-cmd --zone=public --remove-service=http
success
root@odroidc2:/home/qkboo# firewall-cmd --zone=public --remove-service=https
success

Http, Ssh 방화벽 활성화

http, https 를 공개 서비스를 지원하는 기본 존인 public에 추가한다.

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sudo firewall-cmd --add-service=ssh
sudo firewall-cmd --add-service=http
sudo firewall-cmd --add-service=https

sudo firewall-cmd –zone=public –add-service=http –permanent

방화벽을 갱신한다

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firewall-cmd --reload
firewall-cmd --state

혹은 zone을 지정해 추가한다.

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sudo firewall-cmd --zone=web --add-service=ssh
sudo firewall-cmd --zone=web --add-service=http
sudo firewall-cmd --zone=web --add-service=https
sudo firewall-cmd --zone=web --list-all

Likewise, we can add the DNS service to our “privateDNS” zone:

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sudo firewall-cmd --zone=privateDNS --add-service=dns
sudo firewall-cmd --zone=privateDNS --list-all

Zone 에 구성한 서비스 등은 런타임 혹은 완전히 방화벽에 구성할 수 있다.

To change settings in both modes, you can use two methods:
Change runtime settings and then make them permanent as follows:

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firewall-cmd <other options>
firewall-cmd --runtime-to-permanent

Set permanent settings and reload the settings into runtime mode:

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firewall-cmd --permanent <other options>
firewall-cmd --reload

모든 구성 내용 확인:

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$ sudo firewall-cmd --list-all
public
  target: default
  icmp-block-inversion: no
  interfaces:
  sources:
  services: ssh dhcpv6-client http https
  ports:
  protocols:
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:

특정 zone 에 대한 내역을 출력한다:

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$ sudo firewall-cmd --zone=public --list-all
public
  target: default
  icmp-block-inversion: no
  interfaces:
  sources:
  services: ssh dhcpv6-client http https
  ports:
  protocols:
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:

참조

https://www.linode.com/docs/security/firewalls/introduction-to-firewalld-on-centos/

FirewallD

• RedHat: Getting started with firewalld

• How to set up firewalld on CentOS 7

Firewalld configuration and usage

RedHat, CentOS, Fedora 배포본 등에서 표준 방화벽 인터페이스로 제공되는 최신 FirewallD 사용을 시작해 보자. firewalld 패키지 설치는 각 배포본의 방법으로 설치하면 된다.

여기서는 OpenSUSE, Armbian 배포본을 설치한 시스템에서 firewalld 방화벽을 구성하고 설정하는 과정을 요약 정리했다.