I understand the basics of NAT but I've come across an inconsistency in the official material and I'd like to resolve it.
If I'm sitting at a PC in an organisation, the IP address of my PC may be 192.168.123.123 and this is the Inside Local address. The NAT router of the organisation translates this to a registered address, which might be 22.214.171.124 and this is the Inside Global address.
If I access a site, let's say
, this is converted to an IP address by DNS and sends data from my web browser to, for instance, 126.96.36.199. If there's NAT at the far end (the Outside network), this address will be translated to a private address, say 172.20.4.56 and this is the physical server with which I am communicating, but this address is irrelevant to me.
Some of the material refers to 188.8.131.52 as the Outside Global address and 172.20.4.56 as the Outside Local address whilst other material refers to 184.108.40.206 as the Outside Local address and 172.20.4.56 as the Outside Global address. Which is correct?
As a novice, it would be logical if a Local address is that by which a host on a LAN refers to another host on the same LAN whilst a Global address is that by which a host refers to another host on a different LAN under the control of a different organisation. I don't know if this is correct though!
Re: NAT inconsistency in Cisco material
9 years 6 months ago #29012
example, 220.127.116.11 is both the Outside local and the Outside global address. Yes, this might sound odd at the beginning but this is what I just got out from the CCNA academy material.
Inside and Outside refer to the physical location of the host/server.
Local means the IP address as it is seen by the inside network. Global means the IP address as it is seen by the outside/INTERNET (but not necessarily inside the outside network).