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What is the iptables command to achieve the following rule as reported by sudo iptables -t nat -L -n -v

Chain POSTROUTING (policy ACCEPT 133 packets, 10675 bytes)
 pkts bytes target     prot opt in     out     source               destination         
   74  4322 MASQUERADE  all  --  *      *       10.42.0.0/24        !10.42.0.0/24        
  • you can see it by yourself by doing iptables -t nat -S POSTROUTING – LL3 Jul 15 at 16:45
  • Thank you. I also found it the hard way ~~~ sudo iptables --table nat -A POSTROUTING -s 192.168.42.0/24 ! -d 192.168.42.0/24 -j MASQUERADE ~~~ – Gary Smith Jul 15 at 16:49
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As prompted by LL3 above one option is:

sudo iptables -A POSTROUTING -s 192.168.42.0/24 ! -d 192.168.42.0/24 -j MASQUERADE

and another which implicitly refers to the nat table, which I used, is

sudo iptables --table nat -A POSTROUTING -s 192.168.42.0/24 ! -d 192.168.42.0/24 -j MASQUERADE
  • Please note that I prompted a command that prints all current rules of a specific chain, showing the syntax you would need to use to replicate those rules, so that you can see by yourself how a particular rule as shown by -L can be obtained on the command line. Also note that -S output is always relative to the table and chain you specify, meaning that to replicate the same rule you need to specify the table explicitly if it is not the -t filter one. For this reason your first example here will not work because the POSTROUTING chain does not exist in the -t filter table. – LL3 Jul 15 at 17:03

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