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clearing_iptables [2023/05/08 04:23] – -Clarity-intro, formatting hogwildclearing_iptables [2023/05/08 04:48] – -formatting hogwild
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-===== Clearing iptables custom commands prior to re-applying new ones =====+===== Clearing iptables custom commands prior to applying new ones =====
  
-Let's say, for example, you want to use some custom iptables commands in a script/the firewall. This could actually apply to any recurring script (such as WAN Up).+Let's say, as an example, that you wanted to use some custom iptables commands in a script, such as the firewall scriptIn fact, the following principles would apply to any recurring script (such as "WAN Up").
  
-You can remove what previously added iptables directive with a simple approach:+ \\ You can remove previously-added iptables directives using a simple approach:
  
  \\  \\
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  \\  \\
  
-This command here below will check what iptables **-A** (append) or **-I** (insert) have been used in the current Script/Firewall text area and force a run of the same command replacing any **-A** or **-I** with a **-D** (Delete) essentially removing any user added iptables directive. To be noted that for advanced iptables commands a user might have created custom tables, this is usually achieved via "**-N**" (new). You can apply the same principle as per above looking for **-N**Do remember that:+The commands below will check what iptables **-A** (append) or **-I** (insert) directives have been issued previously in the current Script/Firewall text. They will then force a run of the same commandreplacing any instance of **-A** or **-I** with a **-D** (Delete) command. In essence, this will reverse/remove any user-added iptables directives.
  
-  * you need to un-reference the custom table from the built in one first (as per approach above) +A user might have created custom tables in which to use advanced iptables commands. This is usually performed using the "**-N**" (new) command. The same principles described above will also apply to previously-issued directives which used the **-N command**. 
-  * table needs to be empties with **-F** (Flush) first e.g. **iptables -F $TABLE_NAME** + 
-  * only at this point you will be allowed to remove the table with **iptables -X $TABLE_NAME**.+ \\ Here are some rules to remember when using these commands: 
 + 
 +  * First, you need to dereference the custom table from the built-in one, using the above method. 
 +  * table must then be emptied with the **-F** (Flush) switch/parameter (for example, **iptables -F $TABLE_NAME **. 
 +  * Only at this point will you be allowed to remove the table with the command:  **iptables -X $TABLE_NAME** . 
 + 
 + \\
  
  
clearing_iptables.txt · Last modified: 2023/05/08 04:49 by hogwild