Re: NAT - Network Address Translation

From: Juergen P. Meier (news@jors.net)
Date: 06/14/02 

From: "Juergen P. Meier" <news@jors.net>
Date: Fri, 14 Jun 2002 05:37:09 +0000 (UTC)

begin followup to Barry Margolin:
> In article <slrnaggvr7.7q6.I.H.Gregory@ihg0.herts.ac.uk>,
> Ian Gregory <I.H.Gregory@herts.ac.uk> wrote:
>>In article <JJLN8.9$O26.179@paloalto-snr1.gtei.net>, Barry Margolin wrote:
>>>In article <ae7tj2$2pl$1@sapa.inka.de>,
>>>Bernd Eckenfels <ecki-news2002-06@lina.inka.de> wrote:
>>>>Port forwarding is not done in the routing table but with an daemon or a
>>>>special kernel setting. in linux it is done with ipchains or netfilter.
>>>
>>>What are you talking about? Most NAT routers *do* support port forwarding.
>>
>>What are you talking about? That *is* what he said. "Port forwarding"
>>is done by the NAT software (implemented as a kernel module). Routing
>>is done by the standard kernel.
>
> I thought we were talking about NAT routers, like the ones sold by
> companies like Linksys.

Yes, so what? Do you think they contain some magical NAT device?
They are just another piece of Hardware with an Operating System and a
Kernel that does the routing. Just because it's sealed in a box does
not mean its not a computer.
 
> Note that the OP didn't say "routing table", he said "router table",

He also made a few other spelling errors, so what?

> i.e. some configuration table on the router. A router that performs NAT
> generally has a table of static translations, which may contain address
> translations and/or port forwarding entries.

A router that performs NAT does this inside the NAT code. He probably
uses some tables that tell it what to NAT and how.

Black Boxes are usually just regular boxes painted black.

Juergen 

-- 
Juergen P. Meier - "This World is about to be Destroyed!"
This is it. Nothing more to come. There is no more text. It's the
end

Relevant Pages

  • Re: router help needed ....urgent
    ... now what i need is that all my traffic for internet ... >> routing or PBR on cisco, ... If both links are to the same ISP router then you can use BGP ... Why not just put the 2 internet feeds into a hub/switch and connect the router by 1 ethernet port and use IP routing and NAT to determine the best route to use. ...
    (comp.dcom.sys.cisco)
  • Re: Hiding NATs with PF
    ... > router causes upstream routing headaches. ... > penalty is occured by the NAT device itself, as ti does the source port ... it's not uncommon for internal routing infrastructure to be ... > hidden by a NAT that could not be hidden by a single host with firewall ...
    (comp.unix.bsd.openbsd.misc)
  • Re: Simple Routing using FC2/3
    ... >> This silly routing thing is driving me buzzonkers. ... >> first email concerning the gateway address of the LAN PC. ... > the 192.168.213.x addresses back to your router box. ... > NAT on the router box you are describing so all of the 192.168.213.x net ...
    (Fedora)
  • Re: newbie to home network dhcp worries
    ... this is not fine unless the routing has been arranged. ... > using DHCP on the WAN for IP and providing DHCP on the LAN side, ... > router will be fully able to reach the internet. ... you MUST run NAT on at least the Modem(the ...
    (microsoft.public.win2000.networking)
  • Re: [Going nuts] Cant share the connection to the Internet
    ... Have you configured and re-compiled your FreeBSD kernel to support NAT? ... Kernel configuration is covered in chapter 8 of the FreeBSD Handbook ...
    (comp.unix.bsd.freebsd.misc)