2 wire DSL

Sun Dec 7 05:31:59 UTC 2008

--- On Sat, 12/6/08, Luke Militello <luke at digitalenigma.net> wrote:

> From: Luke Militello <luke at digitalenigma.net>
> Subject: Re: 2 wire DSL
> To: "Ubuntu user technical support, not for general discussions" <ubuntu-users at lists.ubuntu.com>
> Date: Saturday, December 6, 2008, 11:18 PM
> Leonard Chatagnier wrote:
> > --- On Sat, 12/6/08, Luke Militello
> <luke at digitalenigma.net> wrote:
> > BIG SNIP
> >> Sounds to me the problem is a double NAT.  From
> what I am
> >> reading... is 
> >> this how your network is setup?
> >>
> >> INET <----> 2WIRE-DSL <----> WIFI-RTR
> >> <----> END-USERS
> >>
> >> Most DSL routers do NAT by default, however lack
> the option
> >> of WiFi 
> >> capabilities so most users opt for a secondary
> router.  If
> >> your network 
> >> is like the one above, then your WiFi router is
> >> "NAT'ing" down to one IP 
> >> address on the "DSL network".  Although
> double
> >> NAT is bad for port 
> >> forwarding and I wouldn't recommend it, it can
> be done,
> >> however you must 
> >> be sure the two private ranges are not
> conflicting.  In
> >> other words, if 
> >> the device doing NAT sees the same network on each
> side, it
> >> will get 
> >> confused.  If this is the case, do something like
> this.
> >>
> >> INET <----> 2WIRE-DSL
> <--(192.168.1.0/24)-->
> >> WIFI-RTR 
> >> <--(192.168.2.0/24)--> END-USERS
> >>
> >> You will still have double NAT in place, but this
> should
> >> allow 
> >> connectivity to 192.168.1.254 (your DSL box). 
> Because this
> >> IP address 
> >> only exists on one side, your WiFi router would
> treat it
> >> like a "public" 
> >> IP and translate it just fine.  Feel free to use
> any of
> >> these networks 
> >> as they are all reserved for private use.
> >>
> >> 10.0.0.0/8 (10.0.0.0-10.255.255.255)
> >> 172.16.0.0/12 (172.16.0.0-172.31.255.255)
> >> 192.168.0.0/16 (192.168.0.0-192.168.255.255)
> >>
> >> However, the best approach would be to directly
> connect one
> >> PC to your 
> >> DSL box (via DHCP), login and disable NAT, connect
> your
> >> WiFi router back 
> >> up, reboot both DSL and WiFi router (in that
> order), then
> >> login to your 
> >> WiFi router and verify for its public address that
> it does
> >> NOT have an 
> >> IP address which falls in the ranges given above.
> >>
> >> One more thing to mention, most DSL routers will
> >> automagically disable 
> >> NAT once they see a connection to the
> WAN/DSL/Internet
> >> side.  In this 
> >> case, your network should be fine.  Simply
> disconnect the
> >> DSL box from 
> >> the phone line, reboot it and you should get
> connectivity
> >> to 
> >> 192.168.1.254 for management purposes.  Once
> plugged back
> >> in to the 
> >> phone line, connectivity to 192.168.1.254 will go
> away. 
> >> However, to do 
> >> this, I would plug a PC directly into the DSL box
> to avoid
> >> network 
> >> confusion if you WiFi router uses the same network
> as your
> >> DSL box (as 
> >> stated above).
> >>
> >> Hope this helps, if not, please enlighten me on
> your
> >> network setup as 
> >> there are too many posts for me to trace back on
> ;)
> >>
> >>
> >>
> > Honestly, Luke, I have no idea what you mean at the
> beginning
> > of your reply so let me try to explain.  Two machine
> LAN.  Outside
> > world connected to 2wire DSL router/ modem combo. 
> Router wired
> > to new Gateway Intrepid machine which is now in shop
> so I have no
> > hard wired maching in place currently.  The other
> machine in anther
> > room has a syslink wmp54g wifi card installed and a
> NIC also but
> > not connected to anything.  The eth0 interface is
> setup with same
> > IP as the wifi.
> > I don't know about NAt either and If I understand
> what you said
> > I don't have a separate router and modem.  They
> are all in one box,
> > a 2wire 1701hg router/modem combo.  I've only had
> experience 
> > with this one router.modem combo.  it seem that you
> refer to
> > each separately above, but I'm not sure.  In any
> case, I'm about
> > to move the wireless machine and hook it up directly
> to the
> > router/modem(after unplugging it to reset) and start
> the machine
> >  back up under DHCP to see if I can connect to
> 192.168.1.254 and
> > access the 2wire setup page again.  Hope this explains
> a liitle.  I
> > know what you mean, I've been answering replyies
> on this issue all
> > day and haven't had time to move the machine or
> switch back to DHCP
> > yet but will do so now.   Thanks for you input.  Sorry
> I didn't uderstand
> > most of it but I did say I was a network idiot in an
> earlier post.
> > Leonard Chatagnier
> > lenc5570 at sbcglobal.net
> > 
> > 
> > 
> 
> No, problem, that does clear some stuff up so ignore the
> bulk of my last 
> reply.  So to clarify, you have (right now) one PC
> connected via 
> wireless to your 2Wire DSL.  You can connect to the
> Internet just fine, 
> but cannot connect to the 2Wire?  Try this command...
>
That's correct.
 
> [luke at Ignignokt ~]$ netstat -nr
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags   MSS
> Window  irtt 
> Iface
> 10.188.39.192   0.0.0.0         255.255.255.192 U         0
> 0 
>   0 eth0	<-- My local network.
> 169.254.0.0     0.0.0.0         255.255.0.0     U         0
> 0 
>   0 eth0	<-- If you have this as well, ignore it.
> 0.0.0.0         10.188.39.193   0.0.0.0         UG        0
> 0 
>   0 eth0	<-- My default gateway.
> 
> 
> See where I have "10.188.39.193"?  That is my
> default gateway hence the 
> "G" flag.  In your case, is yours 192.168.1.254? 
> If it is something 
> different, that is most likely the IP address of your
> 2Wire.  Try 
> connecting to whatever IP address is listed there in
> Firefox.
> 
I have attached the output but it still says my gateway
is 192.168.1.254 which is what it's supposed to be 
the 2wire 1701hg router/modem.  Thanks for trying.

lchata at ubuntu:~$ netstat -nr
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
192.168.1.0     0.0.0.0         255.255.255.0   U         0 0          0 eth0
192.168.1.0     0.0.0.0         255.255.255.0   U         0 0          0 wlan0
169.254.0.0     0.0.0.0         255.255.0.0     U         0 0          0 wlan0
0.0.0.0         192.168.1.254   0.0.0.0         UG        0 0          0 wlan0
0.0.0.0         192.168.1.254   0.0.0.0         UG        0 0          0 eth0
lchata at ubuntu:~$ 

Leonard Chatagnier
lenc5570 at sbcglobal.net