Changes

      

      

===Static NAT===

===Static NAT===

Permanently maps an internal IP address to a public one.  This is useful for allowing (often unsolicited) external traffic into a local server.<ref name="dummies - types of NAT">https://www.dummies.com/programming/networking/cisco/types-of-network-address-translation/</ref>

Permanently maps an internal IP address to a public one.  This is useful for allowing (often unsolicited) external traffic into a local server.<ref name="dummies - types of NAT"/>

===Overloading (or Port Address Translation)===  

===Overloading (or Port Address Translation)===  

IPs are added to the mappings table based on the source and destination ports that are used. Internal devices can always join the internal network and share the external address(es) as long as there are valid port numbers not in use.<ref name="dummies - types of NAT">https://www.dummies.com/programming/networking/cisco/types-of-network-address-translation/</ref>

IPs are added to the mappings table based on the source and destination ports that are used. Internal devices can always join the internal network and share the external address(es) as long as there are valid port numbers not in use.<ref name="dummies - types of NAT"/>

===Overlapping===  

===Overlapping===  

When public addresses are used inside a network (thus overlapping private addresses onto public address space), a public address block can be used on multiple internal networks. Those "internal" addresses can be translated to other public addresses when connected to the "public" side of the router.<ref name="dummies - types of NAT">https://www.dummies.com/programming/networking/cisco/types-of-network-address-translation/</ref>

When public addresses are used inside a network (thus overlapping private addresses onto public address space), a public address block can be used on multiple internal networks. Those "internal" addresses can be translated to other public addresses when connected to the "public" side of the router.<ref name="dummies - types of NAT"/>

==Process==

==Process==

# When another device also initiates a connection to the Internet, its requests are also sent to the router, which passes on those requests to the remote server using this device's unique port number.  This exchange with the router is easily differentiated from the other exchange using port numbers, and delivered to the requesting devices.

# When another device also initiates a connection to the Internet, its requests are also sent to the router, which passes on those requests to the remote server using this device's unique port number.  This exchange with the router is easily differentiated from the other exchange using port numbers, and delivered to the requesting devices.

# When unsolicited traffic comes to the router (a regular occurrence on the Internet), a NAT system alone will attempt to remap this traffic based on the port number is used. If no such port number is in use, it will either drop the packet (ignore it), or reply with an error code stating that the requested device could not be found. However most networks, including most of those behind cheap consumer routers, typically have a [[firewall]] which blocks this kind of traffic, when an internal device did not first contact that external device.

# When unsolicited traffic comes to the router (a regular occurrence on the Internet), a NAT system alone will attempt to remap this traffic based on the port number is used. If no such port number is in use, it will either drop the packet (ignore it), or reply with an error code stating that the requested device could not be found. However most networks, including most of those behind cheap consumer routers, typically have a [[firewall]] which blocks this kind of traffic, when an internal device did not first contact that external device.

<ref name="cisco nat faq">https://www.cisco.com/c/en/us/support/docs/ip/network-address-translation-nat/26704-nat-faq-00.html</ref><ref name="ciscopress nat">http://www.ciscopress.com/articles/article.asp?p=25273</ref><ref name="whatosmyipaddress nat">https://whatismyipaddress.com/nat</ref>

<ref name="cisco nat faq"/><ref name="ciscopress nat"/><ref name="whatosmyipaddress nat"/>

==References==

==References==