howto/networksettings.md
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@@ -7,7 +7,9 @@ The third rule of dn42: Allow ip forwarding!
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No serious, in case some packets are dropped check first if your settings are correct.
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`rp_filter` also known as reverse path filtering is a security measure.
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-When the route to return a packet uses a different interface than it arrived from, the packet is dropped. However dn42 routes can be asymmetric. Which means, packets can take different routes on the return path.
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+When the route to return a packet uses a different interface than it arrived from, the packet is dropped.
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+Some attackers will set a wrong return address on their packets. This security measure was created to address when this happens.
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+However dn42 routes can be asymmetric. Which means, packets can take different routes on the return path.
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That is why `rp_filter` needs to be disabled.
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**Note** using sysctl is not persistent. Depending on your linux distribution put it into `/etc/sysctl.conf` or `/etc/sysctl.d`