操作系统是centos7.2，firewalld版本是0.4.3.2 我禁用了firewalld.service
[root@controller ~]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
Active: failed (Result: signal) since Thu 2017-03-30 23:17:24 CST; 17s ago
Docs: man:firewalld(1)
Main PID: 3417 (code=killed, signal=KILL)
Mar 30 23:15:22 controller.datall.cn systemd[1]: Starting firewalld - dynamic firewall daemon...
Mar 30 23:15:23 controller.datall.cn systemd[1]: Started firewalld - dynamic firewall daemon.
Mar 30 23:17:24 controller.datall.cn systemd[1]: firewalld.service: main process exited, code=kil...ILL
Mar 30 23:17:24 controller.datall.cn systemd[1]: Unit firewalld.service entered failed state.
Mar 30 23:17:24 controller.datall.cn systemd[1]: firewalld.service failed.
Hint: Some lines were ellipsized, use -l to show in full.
[root@controller ~]# ps aux | grep firewalld
root 3640 0.0 0.0 112644 952 pts/0 S+ 23:17 0:00 grep --color=auto firewalld
然后 iptabes-save 命令仍然显示一些规则，如下所示。
[root@controller ~]# iptables-save
# Generated by iptables-save v1.4.21 on Thu Mar 30 23:19:22 2017
*security
:INPUT ACCEPT [359:27396]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [311:43588]
:FORWARD_direct - [0:0]
:INPUT_direct - [0:0]
:OUTPUT_direct - [0:0]
-A INPUT -j INPUT_direct
-A FORWARD -j FORWARD_direct
-A OUTPUT -j OUTPUT_direct
COMMIT
# Completed on Thu Mar 30 23:19:22 2017
# Generated by iptables-save v1.4.21 on Thu Mar 30 23:19:22 2017
*raw
:PREROUTING ACCEPT [422:37323]
:OUTPUT ACCEPT [311:43588]
:OUTPUT_direct - [0:0]
:PREROUTING_direct - [0:0]
-A PREROUTING -j PREROUTING_direct
-A OUTPUT -j OUTPUT_direct
COMMIT
# Completed on Thu Mar 30 23:19:22 2017
# Generated by iptables-save v1.4.21 on Thu Mar 30 23:19:22 2017
*mangle
:PREROUTING ACCEPT [166:15197]
:INPUT ACCEPT [166:15197]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [118:24382]
:POSTROUTING ACCEPT [118:24382]
:FORWARD_direct - [0:0]
:INPUT_direct - [0:0]
:OUTPUT_direct - [0:0]
:POSTROUTING_direct - [0:0]
:PREROUTING_ZONES - [0:0]
:PREROUTING_ZONES_SOURCE - [0:0]
:PREROUTING_direct - [0:0]
:PRE_public - [0:0]
:PRE_public_allow - [0:0]
:PRE_public_deny - [0:0]
:PRE_public_log - [0:0]
-A PREROUTING -j PREROUTING_direct
-A PREROUTING -j PREROUTING_ZONES_SOURCE
-A PREROUTING -j PREROUTING_ZONES
-A INPUT -j INPUT_direct
-A FORWARD -j FORWARD_direct
-A OUTPUT -j OUTPUT_direct
-A POSTROUTING -o virbr0 -p udp -m udp --dport 68 -j CHECKSUM --checksum-fill
-A POSTROUTING -j POSTROUTING_direct
-A PREROUTING_ZONES -g PRE_public
-A PRE_public -j PRE_public_log
-A PRE_public -j PRE_public_deny
-A PRE_public -j PRE_public_allow
COMMIT
# Completed on Thu Mar 30 23:19:22 2017
# Generated by iptables-save v1.4.21 on Thu Mar 30 23:19:22 2017
*nat
:PREROUTING ACCEPT [24:2833]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [5:348]
:POSTROUTING ACCEPT [5:348]
:OUTPUT_direct - [0:0]
:POSTROUTING_ZONES - [0:0]
:POSTROUTING_ZONES_SOURCE - [0:0]
:POSTROUTING_direct - [0:0]
:POST_public - [0:0]
:POST_public_allow - [0:0]
:POST_public_deny - [0:0]
:POST_public_log - [0:0]
:PREROUTING_ZONES - [0:0]
:PREROUTING_ZONES_SOURCE - [0:0]
:PREROUTING_direct - [0:0]
:PRE_public - [0:0]
:PRE_public_allow - [0:0]
:PRE_public_deny - [0:0]
:PRE_public_log - [0:0]
-A PREROUTING -j PREROUTING_direct
-A PREROUTING -j PREROUTING_ZONES_SOURCE
-A PREROUTING -j PREROUTING_ZONES
-A OUTPUT -j OUTPUT_direct
-A POSTROUTING -s 192.168.122.0/24 -d 224.0.0.0/24 -j RETURN
-A POSTROUTING -s 192.168.122.0/24 -d 255.255.255.255/32 -j RETURN
-A POSTROUTING -s 192.168.122.0/24 ! -d 192.168.122.0/24 -p tcp -j MASQUERADE --to-ports 1024-65535
-A POSTROUTING -s 192.168.122.0/24 ! -d 192.168.122.0/24 -p udp -j MASQUERADE --to-ports 1024-65535
-A POSTROUTING -s 192.168.122.0/24 ! -d 192.168.122.0/24 -j MASQUERADE
-A POSTROUTING -j POSTROUTING_direct
-A POSTROUTING -j POSTROUTING_ZONES_SOURCE
-A POSTROUTING -j POSTROUTING_ZONES
-A POSTROUTING_ZONES -g POST_public
-A POST_public -j POST_public_log
-A POST_public -j POST_public_deny
-A POST_public -j POST_public_allow
-A PREROUTING_ZONES -g PRE_public
-A PRE_public -j PRE_public_log
-A PRE_public -j PRE_public_deny
-A PRE_public -j PRE_public_allow
COMMIT
# Completed on Thu Mar 30 23:19:22 2017
# Generated by iptables-save v1.4.21 on Thu Mar 30 23:19:22 2017
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [118:24382]
:FORWARD_IN_ZONES - [0:0]
:FORWARD_IN_ZONES_SOURCE - [0:0]
:FORWARD_OUT_ZONES - [0:0]
:FORWARD_OUT_ZONES_SOURCE - [0:0]
:FORWARD_direct - [0:0]
:FWDI_public - [0:0]
:FWDI_public_allow - [0:0]
:FWDI_public_deny - [0:0]
:FWDI_public_log - [0:0]
:FWDO_public - [0:0]
:FWDO_public_allow - [0:0]
:FWDO_public_deny - [0:0]
:FWDO_public_log - [0:0]
:INPUT_ZONES - [0:0]
:INPUT_ZONES_SOURCE - [0:0]
:INPUT_direct - [0:0]
:IN_public - [0:0]
:IN_public_allow - [0:0]
:IN_public_deny - [0:0]
:IN_public_log - [0:0]
:OUTPUT_direct - [0:0]
-A INPUT -i virbr0 -p udp -m udp --dport 53 -j ACCEPT
-A INPUT -i virbr0 -p tcp -m tcp --dport 53 -j ACCEPT
-A INPUT -i virbr0 -p udp -m udp --dport 67 -j ACCEPT
-A INPUT -i virbr0 -p tcp -m tcp --dport 67 -j ACCEPT
-A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -j INPUT_direct
-A INPUT -j INPUT_ZONES_SOURCE
-A INPUT -j INPUT_ZONES
-A INPUT -m conntrack --ctstate INVALID -j DROP
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -d 192.168.122.0/24 -o virbr0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -s 192.168.122.0/24 -i virbr0 -j ACCEPT
-A FORWARD -i virbr0 -o virbr0 -j ACCEPT
-A FORWARD -o virbr0 -j REJECT --reject-with icmp-port-unreachable
-A FORWARD -i virbr0 -j REJECT --reject-with icmp-port-unreachable
-A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -i lo -j ACCEPT
-A FORWARD -j FORWARD_direct
-A FORWARD -j FORWARD_IN_ZONES_SOURCE
-A FORWARD -j FORWARD_IN_ZONES
-A FORWARD -j FORWARD_OUT_ZONES_SOURCE
-A FORWARD -j FORWARD_OUT_ZONES
-A FORWARD -m conntrack --ctstate INVALID -j DROP
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
-A OUTPUT -o virbr0 -p udp -m udp --dport 68 -j ACCEPT
-A OUTPUT -j OUTPUT_direct
-A FORWARD_IN_ZONES -g FWDI_public
-A FORWARD_OUT_ZONES -g FWDO_public
-A FWDI_public -j FWDI_public_log
-A FWDI_public -j FWDI_public_deny
-A FWDI_public -j FWDI_public_allow
-A FWDI_public -p icmp -j ACCEPT
-A FWDO_public -j FWDO_public_log
-A FWDO_public -j FWDO_public_deny
-A FWDO_public -j FWDO_public_allow
-A INPUT_ZONES -g IN_public
-A IN_public -j IN_public_log
-A IN_public -j IN_public_deny
-A IN_public -j IN_public_allow
-A IN_public -p icmp -j ACCEPT
-A IN_public_allow -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW -j ACCEPT
-A IN_public_allow -p tcp -m tcp --dport 443 -m conntrack --ctstate NEW -j ACCEPT
-A IN_public_allow -p tcp -m tcp --dport 80 -m conntrack --ctstate NEW -j ACCEPT
COMMIT
# Completed on Thu Mar 30 23:19:22 2017
所有 iptables 服务都已被禁用。我现在真的很困惑。谁能告诉我为什么？
[root@controller ~]# systemctl list-unit-files | egrep 'firewalld|table'
ebtables.service disabled
firewalld.service disabled
ip6tables.service disabled
iptables.service disabled
答案1
Firewalld 只是一个管理过滤规则的守护进程。过滤本身是在内核中使用从用户空间加载到内核中的规则完成的。过滤不需要运行活动进程；如果加载了规则，即使firewalld已被终止，内核也会进行过滤。