Linux配置某個IP做網關

服務端

1. 開啓IP轉發

sudo vim /etc/sysctl.conf

# Uncomment the next line to enable packet forwarding for IPv4
# 去掉#號
net.ipv4.ip_forward=1

立即生效
sysctl -p 

2. 設置iptables規則

iptables -t nat -A POSTROUTING -j MASQUERADE

若出現can't initialize iptables table nat': Table does not exist

第一種

如果說nat名字是大寫的NAT 試試iptables -tnat -L

原因是如果使用命令iptables -tNAT -L 是沒有NAT表的也會出現這個錯誤

第二種：
該錯誤完整應該是這樣的：

can’t initialize iptables table `nat’: Table does not exist (do you need to insmod?)

Perhaps iptables or your kernel needs to be upgraded.

首先

[root@localhost ~]# modprobe -l|grep iptable_nat

kernel/net/ipv4/netfilter/iptable_nat.ko

[root@localhost ~]#

嘗試如下操作

[root@localhost ~]# modinfo iptable_nat

filename: /lib/modules/2.6.32-431.el6.x86_64/kernel/net/ipv4/netfilter/iptable_nat.ko

alias: ip_nat

license: GPL

srcversion: 507BCAD1E3A207FDF875EEC

depends: ip_tables,nf_conntrack_ipv4,nf_nat,nf_conntrack

vermagic: 2.6.32-431.el6.x86_64 SMP mod_unload modversions

[root@localhost ~]# insmod /lib/modules/2.6.32-431.el6.x86_64/kernel/net/ipv4/netfilter/iptable_nat.ko

insmod:error inserting ‘iptable_nat.ko’:-1 unknown symbol in module

[root@localhost ~]# modprobe iptable_nat

[root@localhost ~]#

即可

第三種情況：

[root@localhost ~]# ll /lib/modules/

total 4

drwxr-xr-x. 8 root root 4096 Mar 7 11:11 2.6.32-431.el6.x86_64

[root@localhost ~]#

[root@localhost ~]# uname -r

2.6.32-431.el6.x86_64

[root@localhost ~]#

參考文章
https://blog.51cto.com/qidai/1835782
https://blog.csdn.net/xyyangkun/article/details/9010249