Traffic Forwarder using IPTables - Revision history

Leo at 20:27, 6 July 2020

2020-07-06T20:27:15Z

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	To make a ~~linux box~~ act as the gateway for a NAT (in ~~this example, 10~~.10.2.~~0/24) using IPTables, run:~~		To make a Linux host act as the gateway for a NAT using IPTables, there are a few steps to do:
			1. Enable IP forwarding in the kernel
			2. Create a route so the NAT'ed network is routed via the internal interface
			3. Create a NAT on the external interface
			4. Allow traffic from the internal interface to forward through to the external interface.

	# Enables forwarding. Same effect with 'sysctl net.ipv4.ip_forward=1'		These can be accomplished by running the following:
	echo 1 > /proc/sys/net/ipv4/ip_forward		{{highlight\|lang=terminal\|code=
			## Enables forwarding. Same effect with 'sysctl net.ipv4.ip_forward=1'
	# Define $INSIDE as the interface going into the NAT		# echo 1 > /proc/sys/net/ipv4/ip_forward
	# Define $OUTSIDE as the interface going to the internet
			## Define $INSIDE as the interface going into the NAT
	# Route traffic destined to 10.10.2.0/24 to $INSIDE		## Define $OUTSIDE as the interface going to the internet
	route add -net 10.10.2.0/24 dev $INSIDE
			## Route traffic destined to 10.10.2.0/24 to $INSIDE
	# Masquerade traffic going to $OUTSIDE		# route add -net 10.10.2.0/24 dev $INSIDE
	iptables -t nat -A POSTROUTING -o $OUTSIDE -j MASQUERADE
			## Masquerade traffic going to $OUTSIDE
	# Forward traffic coming from $INSIDE		# iptables -t nat -A POSTROUTING -o $OUTSIDE -j MASQUERADE
	iptables -A FORWARD -i $INSIDE -j ACCEPT
			## Forward traffic coming from $INSIDE
			# iptables -A FORWARD -i $INSIDE -j ACCEPT
			}}

			Devices on the NAT should use this Linux host as its gateway.

			You will probably want to run {{code\|iptables-save}} to make the changes persistent after testing.

	~~Add additional tweaks as required to the firewall. You will probably want to run {{code\|iptables-save}} to make the changes persistent.~~


	{{Navbox Linux}}[[Category:Linux]]		{{Navbox Linux}}[[Category:Linux]]
	[[Category:Networking]]		[[Category:Networking]]

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2019-09-01T06:21:34Z

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2017-02-24T19:14:59Z

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	iptables -A FORWARD -i $INSIDE -j ACCEPT		iptables -A FORWARD -i $INSIDE -j ACCEPT

	Add additional tweaks as required to the firewall. You will probably want to run {{code\|iptables-save~~</code>~~ to make the changes persistent.		Add additional tweaks as required to the firewall. You will probably want to run {{code\|iptables-save}} to make the changes persistent.

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2017-02-24T19:13:30Z
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				Revision as of 19:13, 24 February 2017
				
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  iptables -A FORWARD -i $INSIDE -j ACCEPT   iptables -A FORWARD -i $INSIDE -j ACCEPT



Add additional tweaks as required to the firewall. You will probably want to run <code>iptables-save</code> to make the changes persistent. Add additional tweaks as required to the firewall. You will probably want to run {{code|iptables-save</code> to make the changes persistent.



Leo at 06:06, 29 March 2015
2015-03-29T06:06:40Z


				
				
				
				
				
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Add additional tweaks as required to the firewall. You will probably want to run <code>iptables-save</code> to make the changes persistent. Add additional tweaks as required to the firewall. You will probably want to run <code>iptables-save</code> to make the changes persistent.




[[Category:Linux]] [[Category:Linux]]
[[Category:Networking]]
{{Navbox Linux}}





Leo at 05:15, 15 April 2013
2013-04-15T05:15:50Z


				
				
				
				
				
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				Revision as of 05:15, 15 April 2013
				
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To make a linux box act as the gateway for a NAT (in this example, 10.10.2.0/24) using IPTables, run: To make a linux box act as the gateway for a NAT (in this example, 10.10.2.0/24) using IPTables, run:



  # Enables forwarding   # Enables forwarding. Same effect with 'sysctl net.ipv4.ip_forward=1'
  echo 1 > /proc/sys/net/ipv4/ip_forward   echo 1 > /proc/sys/net/ipv4/ip_forward

← Older revision		Revision as of 19:13, 24 February 2017
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	iptables -A FORWARD -i $INSIDE -j ACCEPT		iptables -A FORWARD -i $INSIDE -j ACCEPT

	Add additional tweaks as required to the firewall. You will probably want to run <code>iptables-save</code> to make the changes persistent.		Add additional tweaks as required to the firewall. You will probably want to run {{code\|iptables-save</code> to make the changes persistent.

← Older revision		Revision as of 06:06, 29 March 2015
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	Add additional tweaks as required to the firewall. You will probably want to run <code>iptables-save</code> to make the changes persistent.		Add additional tweaks as required to the firewall. You will probably want to run <code>iptables-save</code> to make the changes persistent.


	[[Category:Linux]]		[[Category:Linux]]
			[[Category:Networking]]
			{{Navbox Linux}}

← Older revision		Revision as of 05:15, 15 April 2013
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	To make a linux box act as the gateway for a NAT (in this example, 10.10.2.0/24) using IPTables, run:		To make a linux box act as the gateway for a NAT (in this example, 10.10.2.0/24) using IPTables, run:

	# Enables forwarding		# Enables forwarding. Same effect with 'sysctl net.ipv4.ip_forward=1'
	echo 1 > /proc/sys/net/ipv4/ip_forward		echo 1 > /proc/sys/net/ipv4/ip_forward