[TriLUG] ATT gigabit internet quick review

[David Burton via TriLUG]

So, is this right, Matthew?

Suppose that your gateway gets external IPv4 address 129.250.123.123. When
you first set up your router, you plug it into the 5268AC gateway, and your
router is given an IP address by the gateway between 192.168.0.2 and
192.168.0.253. Your computer, plugged into your router, gets an IP address
between 192.168.x.2 and 192.168.x.253, where x is != 0 (as configured in
your router's DHCP/LAN settings). Your computer sees the router at
192.168.x.1 (or perhaps 192.168.x.254). It sees the gateway at 192.168.0.1
(or maybe 192.168.0.254). It sees the Internet through two layers of
NAT-ing.

But when you configure DMZ+ in the gateway, and then reboot your router,
instead of getting an IP address between 192.168.0.2 and 192.168.0.253,
your router is given the external IP address, 129.250.123.123, passed on by
the gateway, which the gateway used to have, before DMZ+ was enabled.

Right?  If that's right, then it sounds pretty good, to me!

It also sounds like you could configure whatever DNSs you want in your own
router, and if it's a decent router then the problem of machines on your
LAN not being able to access your server(s) via your external IP address
would also be solved, since that traffic wouldn't even make it up to the
gateway.

Dave



On Tue, Dec 6, 2016 at 3:07 PM, Rogers, Matthew <
Matthew.Rogers2 at allscripts.com> wrote:

> So in DMZ mode the DMZ device shows the external IP which it pulls via
> DHCP.  The ATT device just forwards all traffic to that particular port
> unless it has something in its state table since the ATT router is still
> running.  I turned off the wireless on the ATT device.  It’s important to
> note that the ATT device uses a particular subnet 192.168.1.0 or whatever,
> but prior to the DMZ mode being used – the new router will pull an internal
> IP prior to configuration of DMZ plus mode.  If you duplicate that subnet
> you’ll cause a problem during that configuration change.
>
>
> *...[snip]...*


> *From:* David Burton [mailto:ncdave4life at gmail.com]
> *Sent:* Tuesday, December 6, 2016 10:58 AM
> *To:* Rogers, Matthew <Matthew.Rogers2 at allscripts.com>; Triangle Linux
> Users Group General Discussion <trilug at trilug.org>
> *Subject:* Re: [TriLUG] ATT gigabit internet quick review
>
>
>
> On Sun, Dec 4, 2016 at 5:00 PM, Rogers, Matthew via TriLUG <
> trilug at trilug.org> wrote:
>
> You can set a device in dmz plus mode which is basically a bridge mode.  I
> do this and run my own router and domain controller with dhcp/DNS etc.
>
>
>
> Do you end up with double-NAT using DMZ mode, Matthew, or does your router
> get the external IP address?
>
>
>
> Dave
>