centos7，iptables的导出和重置

默认情况下，iptables-save会导出所有的表和链到标准输出中

$ iptables-save
# Generated by iptables-save v1.4.21 on Mon Aug  8 10:51:28 2022
*nat
:PREROUTING ACCEPT [264:21272]
:INPUT ACCEPT [5:356]
:OUTPUT ACCEPT [403:30153]
:POSTROUTING ACCEPT [403:30153]
: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]
...

可以将它们输出到文件中

iptables-save > iptables_bak

想要再次进行恢复，iptables-restore即可：

iptables-restore <  iptables_bak