Question:
How do I find my exernal IP address for my cable modem?
dinoman411
2007-09-11 13:45:40 UTC
First off I connect to a router then to the modem. I already tried the 192.168.0.1 and that couldn't be found. I have a Motorola 5B5101 SurfBoard cable modem, and my router is a Linksys WRT54GS version 4 wireless router. I basically want to connect to my modem and open some ports that got closed for some reason (port 21 mainly). From what I know i need the modems external IP address to access it because there is a router in teh middle, but I don't know how to get it. So if you have any idea I can find out my modems external ip address or access my modem another way please leave an answer

~Dinoman411
Twelve answers:
GTB
2007-09-11 14:09:05 UTC
Let's clarify things:



1. Your public IP address is provided by your ISP.



2. If you have a static public IP address, you are paying more for it and your ISP has provided it to you (along with the subnet mask, default gateway, and DNS addreses). You must configure your router's WAN port with these addresses.



3. If you have a dynamic public IP address, it will change, usually whenever the router is restarted. You must configure your router WAN port for dynamic IP in this case. The IP changes as said above but you can determine it by going to www.whatismyip.com and it will tell you what it is.



4. There are non-routable IP addresses which are NOT seen on the internet but on the private side of a router. The 192.168.x.y format (where both x can range from 0 to 255 and y can range from 1 - 255) is not routable. This is NEVER your public IP address.



5. You do not open ports in a modem.



6. You open ports in routers when there is a reason to do so. This is done in the router configuration. You need to know whether it is TCP or UDP and you need to know the LAN IP address of the pc (or other LAN device) to which you wish traffic to be directed. This is a LAN IP address and may be in the 192.168.x.y format described above if your router's LAN IP subnet is in the format 192.168.x.0/24 or similar.

7. Since most LAN devices obtain their IP address from a DHCP server, like a router, they are subject to change. If you open a port in a router you must assign it to a LAN device that has a STATIC LAN IP. To do this you must first limit the Router's LAN DHCP range so you have room for static IP addresses and then assign a static IP address on the LAN device by entering the desired LAN IP address, subnet mask, default gateway, and dns server. Usually the default gateway and dns server is the LAN IP of the router in small netoworks. You assign LAN IP addresses on a Windows pc by right clicking on the LAN settings, selecting properties, highlighting Internet Connections (TCP/IP), and manually entering the addresses on the pop up window.

8. Review your router's manual on opening ports - it will describe the router's step by step process for doing this.

9. Whenever you access a wireless router for any matter whatsoever, connect to it using a wired connection, not a wireless connection.

10. When you assign a static LAN IP on your pc, be sure to select the proper LAN connection. If you wish to provide a static IP to your wireless port, be sure to select it, not the wired port for the static IP.

11. You can determine your private LAN IP address by opening command prompt (start, run - type in cmd and hit enter) and type at the prompt "ipconfig /all" and hit enter.
borkowski
2016-09-29 15:10:23 UTC
Cable Modem Ip Address
2016-12-15 16:16:22 UTC
Cable Modem Ip
Remedios
2015-08-20 17:10:39 UTC
This Site Might Help You.



RE:

How do I find my exernal IP address for my cable modem?

First off I connect to a router then to the modem. I already tried the 192.168.0.1 and that couldn't be found. I have a Motorola 5B5101 SurfBoard cable modem, and my router is a Linksys WRT54GS version 4 wireless router. I basically want to connect to my modem and open some ports that got...
2007-09-11 13:53:34 UTC
your public IP will be found by going to a site like

IPchicken.com

being able to browse to that may be a different story though.

I'd connect directly to the modem with a pc and skip the router, then see what DHCP IP settings I got. mainly the Gateway IP

which is then the LAN IP you're looking for. If this is a cable company provided modem it will usually be a different subnet from what your router is kickin' out.
bsbro
2007-09-11 14:44:23 UTC
Are you trying to host a FTP, Web server, or a mail server on your computer? If you do it through your router its a bit complicated, because, as you already found out, your router gives you your own IP in the private network your router is configured to. There are ways to configure your router so you can hook up your pc to your router and still be able to access it from outside, but that is a bit more complicated to explain on yahoo answers.



To find the ip address, do this, get online with just your modem connected directly to your PC. Take your router out of the equation. Once you get online, go to start-->run-->and then type in "cmd" (without the quotations of course). This black window will pop up, then you type "ipconfig /all" and it will give you your ipaddress. Be aware that your ipaddress maybe dynamic instead of static. I'm not sure who your ISP is so you may have an ipaddress that changes every time you log onto your IPS's network. If you have a dynamic IP address, you can go to www.no-ip.com and download their software which will allow you to type in your address (i.e. d411.myftp.org) and direct it to your pc.



Also, port 21 as well as the default port for webservers (80) is usually blocked by defualt by your ISP. You want to change your port numbers to a port number that isn't blocked (i.e. 8000). Unless you call your ISP to have those ports unlocked (which they will either ask you to change your plans and charge you more), you may want to use other numbers.



Hope this helps.
Mary
2016-03-17 06:52:21 UTC
Yes, you can use another cable modem in your house. Yes, that will generate a second ip address. Yes, you will have to pay for a 2nd internet service from Time Warner, doubling your internet bill.
2016-05-25 11:11:52 UTC
Get a No Cost Background Check Scan at https://bitly.im/aOm7P



Its a sensible way to start. The site allows you to do a no cost scan simply to find out if any sort of data is in existence. A smaller analysis is done without cost. To get a detailed report its a modest payment.



You may not realize how many good reasons there are to try and find out more about the people around you. After all, whether you're talking about new friends, employees, doctors, caretakers for elderly family members, or even significant others, you, as a citizen, have a right to know whether the people you surround yourself with are who they say they are. This goes double in any situation that involves your children, which not only includes teachers and babysitters, but also scout masters, little league coaches and others. Bottom line, if you want to find out more about someone, you should perform a background check.
Diena
2016-01-31 15:45:55 UTC
find exernal ip address cable modem
WHO
2007-09-11 13:56:02 UTC
Hello Dinoman411 try this :)



1) Power down all computers, the router, and the modem, and unplug them from the wall.

2) Disconnect all wires from the router.

3) Power up the router and allow it to fully boot (1-2 minutes).

4) Press and hold the reset button for 30 seconds, then release it, then let the router reset and reboot (2-3 minutes).

5) Power down the router.

6) Connect one computer by wire to port 1 on the router (NOT to the internet port).

7) Power up the router and allow it to fully boot (1-2 minutes).

8) Power up the computer (if the computer has a wireless card, make sure it is off).

9) Try to ping the router. To do this, click the "Start" button > All Programs > Accessories > Command Prompt. A black DOS box will appear. Enter the following: "ping 192.168.1.1" (no quotes), and hit the Enter key. You will see 3 or 4 lines that start either with "Reply from ... " or "Request timed out." If you see "Reply from ...", your computer has found your router.

10) Open your browser and point it to 192.168.1.1. This will take you to your router's login page. Leave the user name blank, and in the password field, enter "admin" (with no quotes). This will take you to your router setup page. Note the version number of your firmware (usually listed near upper right corner of screen).



IN short the login in to your router is 192.168.1.1. :)
2016-09-21 06:30:09 UTC
Awesome answers
2016-08-24 19:30:50 UTC
thank you for the answers everyone <3


This content was originally posted on Y! Answers, a Q&A website that shut down in 2021.
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