IP Forwarding: Difference between revisions

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Line 21: Line 21:
  net.ipv4.ip_forward = 1
  net.ipv4.ip_forward = 1


Alternative (mentioned by Docker documentation):
Alternative (mentioned by [[Docker_Network_Operations#Enable_IP_Forwarding_from_Containers_on_the_Default_Bridge|Docker documentation]]):


  sysctl net.ipv4.conf.all.forwarding=1
  sysctl net.ipv4.conf.all.forwarding=1

Revision as of 17:09, 30 April 2018

External

Internal

Overview

"IP forwarding" is a synonym for "routing." It is called "kernel IP forwarding" because it is implemented in the Linux kernel.

A host that acts as a router has multiple network interfaces. If traffic comes in on one interface and its target subnet is serviced by another network interface, the kernel may forward the packet between interfaces, if it is configured to do so.

echo 1 > /proc/sys/net/ipv4/ip_forward

To enable IP forwarding at boot, add the following to /etc/sysctl.conf:

net.ipv4.ip_forward = 1

Alternative (mentioned by Docker documentation):

sysctl net.ipv4.conf.all.forwarding=1