I can't get ports open on my surfboard 5120 modem, the router is configured properly and it showed them open when I first set it up but they closed and now I can't get them to open again. Once after switching modems it worked briefly but I think the router updated itself or something and the ports are now closed again

The SBV5120 is simply a device that converts your cable internet signal to a RJ45 computer output that connects to your single PC
It also has two RJ11 phone jacks if you use the modem as your home phone as well. It has no wireless function,
For you to have a wireless connection, you will need to purchase a Wifi Router. These can easily be got at any local computer store or a big box retailer like Best Buy, Staples, Computer City etc,
Most come as a 4 or 8 port wifi router, your choice will be the number of wired connections. In your case it looks like one.
Once you have your router, connect the Modem RJ45 to the WAN input on the router and your PC to one of the LAN ports on the router. In its default state, it should connect you to the internet as normal.
The router will have setup instructions which you can use after you connect the modem and PC.

I was banging my head for 2 days with about 35 different configurations and finally tried the following and it worked just fine. Also, tried connecting 3 computers and they all connected with "NO" issues. Even connected wireless with "NO" issues. Now I am at 20mb download speed...J compared to AT&T 1.5mb download speed.

This is my DLINK model -> (DIR-601 Wireless N 150 Home Router Wireless router)

1. Reset your Comcast Surfboard Cable Modem by unplugging it for 5 minutes.

2. Then reset your DLINK Router to the manufactures default settings. Then Unplug DLINK Router for 1 minute then plug it back in (Just plug your cat5 cable into port 1 and connect it to your computer) there should not be anything else plugged into the DLINK Router at the time you make the changes. Just 1 computer can be connected.

3. Went into the DLINK configuration 192.168.0.1 and changed the PPPOE setting that I was using for my AT&T Modem to Dynamic IP (DHCP). Once you make the changes save them and then unplug your DLINK Router it's off.

4. Turn on Comcast Surfboard Cable Modem and wait until all lights are on. Now plug in a cat5 cable from the Surfboard Comcast modem (NOT A CROSSOVER CABLE LIKE THE CD INDICATES) to the INTERNET port of your DLINK Router. Now turn on your DLINK router.

5. Then turn on your computers or restart them and it will pick up IP Addresses from your DLINK Router

Certainly not. You just have to choose between the two.

Certainly you cannot. You just have to choose what connection to use. USB or Ethernet port.

Hi, follow the steps below to configure MR814 with your motorola surfboard:

CONNECTIONS:

1. Connect a Ethernet cable from the modem to the WAN port of the router (isolated port).
2. Connect the computer to the router using any one of the 4 available ports. Please make sure that there is no direct connection between the modem and the computer (either using Ethernet cable or USB cable).
3. Power off the modem and the router after making the connections.
4. Power on the modem and wait for the lights, then power on the router.
RECONFIGURE:
1. Open the browser (Internet Explorer, Mozilla Firefox or Safari).
2. Access the router, usually with http://192.168.0.1
3. Login to the router with the Username as "admin" and Password as "password" (please note that the Username and Password are case sensitive).
4. Click on 'Basic settings' from the left menu and select 'Use Computers MAC Address' from 'router MAC Address' section.
5. Click Apply.
6. Once it updates the settings then power off the modem and the router. Power on the modem and wait for the lights, then power on the router.

I hope this information allows you to resolve this issue.

If I have helped you, please help me, and rate this suggestion with the highest FixYa rating. If you cannot rate this post with the highest rating, then please comment to this post and I will try to help you further.

Regards
Anand

plz check the firewall of the router as well.they tend to close the ports to avoid malicious attacks..try it..if it doesnt work,,keep me posted

There's another option to configure the security or encryption using your SBG 900

Connect your computer to one of the LAN ports
Access the configuration of the modem (example 192.168.254.1)
The if you got the configuration page open find the wireless settings and configure the WPA or WEP security using your modem.

If the modem is actually passing out DHCP, then you have to connect the modem to the router 4 port lan side and not the wan port. Give the router a static ip like 192.168.1.2 and you can talk to it and configure the wireless features.

The easiest way to fix this problem is to not use the software CD that came with you WRT54G. If you type in the ip address of the router (usually for this model the default is 192.168.1.1) in the web browser, you should come to the firmware on the router. After that, log in to the router (usually the user name is admin and the password is either blank or admin). This will show you all of the configurations for the router. Make sure on the first page you have your router set up as DHCP. This will have the modem give your "router" an ip address from your cable company. From there you can set up you router your self.

If theres a open plug-in you should