Hi guys, I'm no networking expert but heres my situation:

I have a desktop pc using high-speed INTERNET through my cable TV motorola modem. It only has one output for LAN, I also have ps3 . I connected a 4-port hub Dlink router hoping to play ps3 and surf the net at the same time, but its only working for pc. If i disconnect the pc and restart the modem it works for ps3. The cable told me to buy a link sys modem that it has an open DNS. He also told me to call dlink if I want. Is there a way I can play ps3 and surf the net at the same time using two router modems? or am I just making this hard on myself? I tried calling Dlink but no one is picking up...

Hi DragonQuest,

It sounds like your cable modem is operating in bridged mode instead of NAT (network address translation) mode. In bridged mode, the modem basically acts as a simple, transparent connection between the LAN port and the WAN/ISP. Since your WAN connection is only ever assigned one IP address from the ISP, only one device can ever actually be connected. NAT, on the other hand, creates a virtual address pool, and translates data going from/to the single WAN IP to the multiple LAN devices, each with its own virtual, or private, IP.

I suspect your DLink hub is either not a router, as you stated, or is not properly configured for NAT. Depending on where you are, you'll likely already know someone who can easily reconfigure your hub/router, or even your cable modem. Among computer "experts", this is a relatively simple, low-level task.

Good luck and hope that clears things up for you.

Chevy

Some model numbers for the D-link etc would help us give more precise advice.

Some model numbers for the D-link etc would help us give more precise advice.

MODEL NUMBER IS DSL2542B

How do I configure it to be NAT? It is a router/modem 4 port hub. I called my cable company, and they came over today, two guys. They both looked at it for about a half an hour and told me you cant, and said only one at a time. The he mentioned I pick up a link sys router for 2000 baht, but thats what I paid for my Dlink router so whats the point? should be the same right? He then asked me to call dlink which I did but they speak Thai not English. PS3 customer support is in Hong Kong or Singapore so I'm not about to call international for this to run up a phone bill.I might have a chance calling ps3 us tech support, but I'm confused about this, should I call dlink support, ps3 support or motorola support?

my motorola model number is MOTOROLA SURFBOARD CABLE MODEM SB5120

I basically want to just surf the INTERNET(on my Desk top PC) and play Final Fantasy 14 on ps3(at the same time) when it comes out soon, so I wont have to keep unplugging the cable and resetting the modem each time, its kind of a hassle to do that if you know what I mean.

Your DLink is an ADSL router with a 4 port switch.

This normally means that if you plug 2 ethernet devices in it is only acting as a switch, it functions as a router only via the ADSL.

Since you are not using the ADSL you essentially have a glorified switch with unused ADSL and routing capabilities.

What you want is an ethernet router, where you plug the ethernet output from your cable modem in the routers WAN port and your other devices into the routers LAN port.

Linksys WRT54GL is a great model for this, which includes 4 LAN ports, wifi and when installed with the tomato custom firmware will outperform much more expensive devices.

Please Note: I have never used your model of router so I may be wrong, but this is the typical scenario for similar devices.

Innerspace pretty much covered it. The DSL router does act as a NAT device, but only when translating between the uplink (RJ-11 telephone jack) and the LAN ports. I did a little Googling and except for the SBG9000, no Surfboard cable modem supports any kind of address translation. You will need another device to share the connection between multiple users/devices.

I'm using a D-Link DIR-300 wireless router w/ 4-port switch, which cost only around ฿1500 when I bought it two years ago. I'm pretty happy with it. The "free" ADSL router that came with my service only has a single LAN port, and I didn't feel the need to spend ฿2000+ to get an ADSL router w/ wifi and switch. Your setup would be very similar -- basically, you'd just connect the Surfboard to the router's uplink port (labeled "Internet" on the DIR-300), and go through the setup wizard. Whatever router you get, I would advise setting up a wireless key (in short, an encryption password) so that your neighbors don't ride free on your connection. And if you have tech-savvy friends handy, take one with you to the shop. There's only so much we can do to help via forum.

Ya I'm not using the telephone jack on the dlink, the cable modem on the motorola only has 1 LAN jack so I plugged that into the dlink and then my pc plugs into the dlink for the INTERNET. When I plug multiple devices into the dlink, the lights are flashing green, even the ps3 sees the IP address but the INTERNET connection failed error code 80710102 DNS error. Is there a way I can configure this set up? I heard of port forwarding but not quite understand it. Also I tried using googles free DNS 4221 and 4223 but its also not working, Ive been trying to work on this for 2 days now and I'm scratching my head, hopefully I can get it to work? I don't really feel like coughing up another 1.5 2k on a new router(If I can get it going) ; ; I don't have any tech savvy friends either ; ;

I'm also using a wired connection, not wireless.

It's not DNS that's the problem, it's the addressing. You need some kind of router, there's no way around it really, unless you want to buy a second network card, install it in your PC, and set up Internet Connection Sharing. Considering your level of knowledge and deficiency in geek friends, that may not be the way you want to go. It would be cheaper, that's for sure. (~200 baht) However, it would probably slow down your PC a little while someone's gaming online on the PS3.

I'm not sure what you mean by "I'm also using a wired connection, not wireless." The wireless part is for your equipment, such as a notebook or wifi-capable phone, not for the upstream connection to your provider.

If all your devices are physically connected to the LAN, I suspect a non-wifi Ethernet router should run no more than 1000 baht.

Here, just so you get an idea on pricing: New B-Link BL-RT05 4-port broadband router, selling on eBay with free worldwide shipping. USD 16.88, or about 530 baht, originating from

Shenzhen, China (across the border from Hong Kong).

http://cgi.ebay.com/Router-4ports-10-100M-Multi-function-Broadband-Router-/230511741504

B-Link isn't bad, as I recall. Their enterprise-level switches and routers are actually higher spec than the equivalent Cisco equipment. YMMV, as I believe home/SOHO devices are new for them. If you're willing to wait a few days for shipping while minimizing expense, this might be the way to go.

Thank You all for your comments, so basically I cant do it then right? I thought of messing with the network a bit but it seems I dug a deeper hole than I should have.

Looking at the specs, you should be able to use the D-link box as your modem/router,

plugged into the phone line instead of the Motorola box.

Then plug the PC into one port and the PS3 into another.

You may need a little assistance from your Internet provider to set

up the D-link correctly.

Do you have Admin access to the Motorola to read off the settings?

http://broadband.motorola.com/consumers/products/sb5120/

http://www.dlink.com.my/products/?idproduct=295&idCategory=200

Looking at the specs, you should be able to use the D-link box as your modem/router,

plugged into the phone line instead of the Motorola box.

That might have worked, except OP has cable internet (coaxial), not ADSL (RJ-11).

Is the true cable modem and NAT/router with CAT5 LAN? Most likely it is - you don't need two routers. Run a 400 baht switch (4 ports) plugged into the true modem and it will automatically provide the extra ports that you don't have on the true modem. done.

Is the true cable modem and NAT/router with CAT5 LAN? Most likely it is - you don't need two routers. Run a 400 baht switch (4 ports) plugged into the true modem and it will automatically provide the extra ports that you don't have on the true modem. done.

I take it you either didn't fully read through the previous posts, or misunderstood something. Here's a recap:

1. The cable modem is one of the Motorola Surfboard series, only one model of which has NAT capability. OP does not have that model.
2. The DSL router has NAT capability and a four-port switch, but the NAT only functions between the telephone jack and the four LAN ports.
3. As is, the DSL router OP is using is basically functioning as a glorified hub/switch. The extra ports are there, but they're useless because there's no NAT.

Network Address Translation has to happen somewhere between the coaxial cable connection and the LAN ports. The DSL router does this only between the telephone jack and the Ethernet ports -- it's a limitation of the hardware and a matter of economics. By and large, the typical consumer will need either a DSL router+switch or an Ethernet-based broadband router; a more expensive single device that can function as either would not sell very well.

Unless someone knows of a cheap, easy way to take the cable internet connection, either by demodulating the signal off the coax directly or by using the Ethernet port, and translate it through something that emulates a DSLAM, and then connect it to the RJ-11 jack on the DSL router, it's going to need another router sitting off the cable modem. (Could be an interesting project....)

OP can a) buy a cable modem/router with or without integral switch (s/he already has a DSL router that acts as switch/hub); get a broadband router like the LinkSys and B-Link already mentioned; c) get DSL internet, several options available; or d) live with what s/he's got, and only have one thing connected to the internet at any one time.

I think this horse is pretty well dead and bloody. Remember, kids, try to read through all the posts before replying. And don't forget to tip your waiter.

Thank you very much for all your posts and replies, I was thinking about buying that 400 baht switch at panthip, but it looks like I'm dead in the water, for now I'll just disconnect my dlink hub and just use the motorola for now. Once my game comes out in march 2011 I'll just have to switch the LAN cable over to the PS3, I was hoping I could use my pc while playing ps3 on-line but o well, BTW I'm not using true cable, its another smaller company called http://www.wycables.com/, but I think I should move and get tot or true, they seem to be a better company with higher speeds. About the DSLAM thats taking way out of my league lol I don't even know where to begin on that project hahaha but ya I think I'll just settle for less, I was hoping I just enter some numbers but its seems its not that easy lol Thx guys(I'm learning) BTW My apartment wont allow me to have my own phone line thats why I couldn't get true or tot, but since the building has cable, I can get INTERNET through that. So I had no choice, at it sucks too because when I got it they told me 4Meg 590 baht, and now I'm only getting 3meg at 650 baht ; ;