Re: Why does dhcpd have a routers (plural) option for a subnet?

On Thu, Sep 26, 2024 at 11:04:51AM -0500, Doug McIntyre wrote:

>You have to think back to when this would have been developed.
>
>The model of NAT didn't exist. IP addresses were unique and globally 
>routable.

...

>Now, with NAT being prevelent everywhere, you're going to have to go
>through the device that holds your session table to have NAT work
>back. Most firewalls won't let traffic coming in on the "wrong"
>interface from passing through. Thus, we've collapsed everything down 
>to requiring
>the one gateway router/firewall device.
>
>This is one of the problems with NAT that old network people complain about.
>NAT solved the Internet IP address limit problem, but with much 
>reduced functionality and resiliency.

Yep.

NAT is a temporary kluge, a bridge to the real solution: IPv6.  IPv6 
doesn't need NAT, because it has plenty of addresses.

You might be interested in RFC 1958: Architectural Principles of the 
Internet[1].  This is fairly short, 5-6 pages.

There's also RFC 4924: Reflections on Internet Transparency[2].  This 
is sort of an update, status of the end-to-end principle (when it was 
written).


[1] <https://www.rfc-editor.org/rfc/rfc1958.html>
[2] <https://www.rfc-editor.org/rfc/rfc4924.html>