CentOS做nat

先參考CentOS安裝dhcp做好dhcp,再做nat,這個CentOS linux就是一台ip分享器

允許ip 傳送

• # echo "1" > /proc/sys/net/ipv4/ip_forward 

查看nat table,目前沒有設定

• #iptables -t nat -L

Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination

Chain POSTROUTING (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

 設定iptables

• # iptables -t nat -A POSTROUTING -s 192.168.182.0/24 -o eth0 -j SNAT --to 140.137.217.94

• -t nat (nat table)
• -A (append)
• POSTROUTING (post routing在路由之後進行)
• eth0 (server上的網卡代號)
• -o (output)
  
• -s (source)
• 192.168.182.0/24 (如果沒有/24,表示以單機192.168.182.0處理)
• -j (jump)
• SNAT (source NAT)
  
• --to (超過二個字的指令要用--)

• #iptables -t nat -L

Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination

Chain POSTROUTING (policy ACCEPT)
target     prot opt source               destination
SNAT       all  --  192.168.182.0/24     anywhere            to:140.137.217.94

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

相關資料可參考OpenSuse做nat