Differences

This shows you the differences between two versions of the page.

--- ubuntu:networking:configuration:ip_forwarding [2021/07/26 11:02] – peter
+++ ubuntu:networking:configuration:ip_forwarding [2021/07/26 11:19] (current) – [Check if Port Forwarding is Enabled] peter
@@ Line 5: / Line 5: @@
 ----
-===== Enable Port Forwarding =====
+===== Enable Port Forwarding Permanantly =====
 Uncomment or add this line to  **/etc/sysctl.conf**:
@@ Line 13: / Line 13: @@
 </file>
-Then  run:
+To enable the changes made in sysctl.conf, run:
 <code bash>
 sysctl -p
 </code>
+----
+===== Enable IP Forwarding on the fly =====
+To enable IP Forwarding, without rebooting the system:
+<code bash>
+sysctl -w net.ipv4.ip_forward=1
+</code>
+or
+<code bash>
+echo 1 > /proc/sys/net/ipv4/ip_forward
+</code>
+<WRAP info>
+**NOTE:**  The setting is changed instantly.
+  * However the result will not be preserved after rebooting the system.
+</WRAP>
+----
+===== Check if Port Forwarding is Enabled =====
+<code bash>
+cat /proc/sys/net/ipv4/ip_forward
+</code>
+returns:
+<code bash>
+</code>
+<WRAP info>
+**NOTE:**
+  * **0**:  Port forwarding is not enabled.
+  *  **1**:  Port forwarding is enabled.
+</WRAP>