CentOS 7 iptables 重启后不持久

Question

我在开发服务器上安装了一个最小的 CentOS 7 版本，以使用 kvm/qemu 虚拟化一些 linux 来宾。

要使用 iptables 而不是firewalld我安装iptables-service并执行以下操作：

systemctl stop firewalld
systemctl mask firewalld
systemctl enable iptables
systemctl start iptables

通过编辑/etc/sysconfig/selinux.

我对 iptables 的规则如下：

iptables -Z
iptables -F
iptables -X
iptables -t nat -Z
iptables -t nat -F
iptables -t nat -X
iptables -t nat -A POSTROUTING -o enp6s0 -j MASQUERADE
iptables -A FORWARD -i enp6s0 -o virbr0 -j ACCEPT

现在我使用以下命令保存我的设置：

iptables-save > /etc/sysconfig/iptables

我的iptables-file样子：

# Generated by iptables-save v1.4.21 on Thu Aug 20 10:46:40 2015
*mangle
:PREROUTING ACCEPT [16736:10889078]
:INPUT ACCEPT [1063:106860]
:FORWARD ACCEPT [15679:10784186]
:OUTPUT ACCEPT [570:71275]
:POSTROUTING ACCEPT [15728:10809742]
-A POSTROUTING -o virbr0 -p udp -m udp --dport 68 -j CHECKSUM --checksum-fill
COMMIT
# Completed on Thu Aug 20 10:46:40 2015
# Generated by iptables-save v1.4.21 on Thu Aug 20 10:46:40 2015
*filter
:INPUT ACCEPT [868:81772]
:FORWARD ACCEPT [8328:7311589]
:OUTPUT ACCEPT [233:32016]
-A FORWARD -i enp6s0 -o virbr0 -j ACCEPT
COMMIT
# Completed on Thu Aug 20 10:46:40 2015
# Generated by iptables-save v1.4.21 on Thu Aug 20 10:46:40 2015
*nat
:PREROUTING ACCEPT [1308:86998]
:INPUT ACCEPT [77:12475]
:OUTPUT ACCEPT [1:72]
:POSTROUTING ACCEPT [1228:74319]
-A POSTROUTING -o enp6s0 -j MASQUERADE
COMMIT
# Completed on Thu Aug 20 10:46:40 2015

快速检查一下我的规则现在是否正确：

[root@dev1 ~]# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination         

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     all  --  anywhere             anywhere            

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination 

但是重新启动服务器后，iptables 规则如下所示：

[root@dev1 ~]# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     udp  --  anywhere             anywhere             udp dpt:domain
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:domain
ACCEPT     udp  --  anywhere             anywhere             udp dpt:bootps
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:bootps

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     all  --  anywhere             10.0.1.0/24          ctstate RELATED,ESTABLISHED
ACCEPT     all  --  10.0.1.0/24          anywhere            
ACCEPT     all  --  anywhere             anywhere            
REJECT     all  --  anywhere             anywhere             reject-with icmp-port-unreachable
REJECT     all  --  anywhere             anywhere             reject-with icmp-port-unreachable
ACCEPT     all  --  anywhere             anywhere            

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     udp  --  anywhere             anywhere             udp dpt:bootpc

我不明白其他规则从何而来。

调用时iptables-restore -c /etc/sysconfig/iptables会显示预期的规则。

似乎保存的规则没有在启动时加载，或者“默认”规则没有刷新或其他什么。

这里有什么问题 ？？？我的头发慢慢变白了...

---

感谢您的快速回复:)

如上所述，我安装了 iptables-services：

[root@dev1 ~]# rpm -aq iptables-services
iptables-services-1.4.21-13.el7.x86_64

启用服务systemctl enable iptables.service而不是使用systemctl enable iptables似乎没有区别，因为链接了相同的服务文件：

[root@dev1 ~]# systemctl disable iptables
rm '/etc/systemd/system/basic.target.wants/iptables.service'
[root@dev1 ~]# systemctl enable iptables.service
ln -s '/usr/lib/systemd/system/iptables.service' '/etc/systemd/system/basic.target.wants/iptables.service'

这是调用后iptables文件的内容 /usr/libexec/iptables/iptables.init save

[root@develcluster1 ~]# cat /etc/sysconfig/iptables
# Generated by iptables-save v1.4.21 on Fri Aug 21 14:34:04 2015
*nat
:PREROUTING ACCEPT [351490:22546787]
:INPUT ACCEPT [15751:2400243]
:OUTPUT ACCEPT [324:21186]
:POSTROUTING ACCEPT [304860:18293418]
-A POSTROUTING -o enp6s0 -j MASQUERADE
COMMIT
# Completed on Fri Aug 21 14:34:04 2015
# Generated by iptables-save v1.4.21 on Fri Aug 21 14:34:04 2015
*filter
:INPUT ACCEPT [505048:69178501]
:FORWARD ACCEPT [55815086:22035726185]
:OUTPUT ACCEPT [325986:56595531]
-A FORWARD -i enp6s0 -o virbr0 -j ACCEPT
COMMIT
# Completed on Fri Aug 21 14:34:04 2015
# Generated by iptables-save v1.4.21 on Fri Aug 21 14:34:04 2015
*mangle
:PREROUTING ACCEPT [109215513:66867793592]
:INPUT ACCEPT [505243:69203589]
:FORWARD ACCEPT [108710264:66798590873]
:OUTPUT ACCEPT [326323:56634790]
:POSTROUTING ACCEPT [109036066:66855179944]
-A POSTROUTING -o virbr0 -p udp -m udp --dport 68 -j CHECKSUM --checksum-fill
COMMIT
# Completed on Fri Aug 21 14:34:04 2015

重启后调用iptables -L不显示我保存的规则：

[root@dev1 ~]# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     udp  --  anywhere             anywhere             udp dpt:domain
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:domain
ACCEPT     udp  --  anywhere             anywhere             udp dpt:bootps
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:bootps

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     all  --  anywhere             10.0.1.0/24          ctstate RELATED,ESTABLISHED
ACCEPT     all  --  10.0.1.0/24          anywhere            
ACCEPT     all  --  anywhere             anywhere            
REJECT     all  --  anywhere             anywhere             reject-with icmp-port-unreachable
REJECT     all  --  anywhere             anywhere             reject-with icmp-port-unreachable
ACCEPT     all  --  anywhere             anywhere            

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     udp  --  anywhere             anywhere             udp dpt:bootpc

也许我在做一些根本性的错误。但是我阅读的每个线程都以相同的方式执行此操作，并且应该可以正常工作。

如果您需要更多信息，请告诉我。

同时，我通过调用一个小脚本来帮助我，我必须在每次重新启动后调用该脚本。

#!/bin/sh

iptables -Z
iptables -F
iptables -X
iptables -t nat -Z
iptables -t nat -F
iptables -t nat -X
iptables -t nat -A POSTROUTING -o enp6s0 -j MASQUERADE
iptables -A FORWARD -i enp6s0 -o virbr0 -j ACCEPT

iptables --flush
iptables-restore -c /etc/sysconfig/iptables

那不是性感，但到目前为止有效。但不可能是最终的解决方案。

Answer 1

我认为您需要通过以下方式启用该服务：

systemctl enable iptables.service

并且您需要运行 iptables init 脚本来保存您的规则，如下所示：

/usr/libexec/iptables/iptables.init save

Answer 2

确保您安装了 iptables-services 包：

rpm -aq iptables-services

如果没有安装：

yum install iptables-services

然后，您可以使用 service 命令来控制它，就像使用以前版本的 CentOS 一样：

service iptables save

的save，stop，start，restart命令将所有的工作，它应该在引导加载。