Cannot get external IP address from router 1

[kev01]

Hi,

I have just bought a NETGEAR cable/DSL router (FR114P) and plugged it in between one PC and my cable modem. But, since then I am not able to get an external IP from my ISP and thus not able to access the net thru my router! :-(

I am able to access the router web configuration interface and my client is is able to get an internal IP from the router (within 192.168.0.2 to 192.168.0.255).

My router though detects that I have a static external IP (which is not correct coz my extermal IP get changed every 2/3 days). I have thus configured my router with a static IP, subnet mask, default gateway and DNS server..but it still doesn't work. :-(


Is it because my ISP allow only one Ethernet MAC address to be connected to the net?? well, i have 2pcs at home..and i don't have any problem accessing the net with either PCs..or does the ISP look at the MAC address of the broadband modem?

- My ISP doesn't require a login program
- When I try to ping the ISP DNS server, I am getting a 'Request Timed out'.

I would be very grateful if someone could tell me why i cannot get any external IP address from my ISP.

Thanks in advance,

 

[mgooder]

Most ISP's hand out IP's via DHCP. You may need to contact your ISP and make sure they support DHCP or that they allow you to have a static IP.

Rico

 

[jfwebber]

Depending upon who your ISP is, some register your MAC address of your NIC at the time of installation. If this is your case, you must change the MAC address of the WAN side of your NETGEAR router to the MAC address that is registered with your ISP. I believe you can do this with the NETGEAR model you have.

Jim

Jim Webber
Network Administrator MCSE CNA

 

[Seaspray0]

The issue here is DHCP, or dynamic hosting of the ip addresses. First off, you are not going to get a dynamic address from your ISP to your computer if you have put a router like that inbetween. You will also need to impliment the NAT (or ICS) capabilities of your router. What needs to happen is the following...

Your router gets a dynamic ip address assigned to it on the port that is connected to your cable modem from the ISP. Your router will assign addresses to the computers hooked up to it on the private home port(s). Typically they assign addresses in the range of 192.168.0.2 through 254. The Network Address Translation (NAT) feature (or called ICS) of the router will translate requests made by your home side to the internet side, replacing your home ip address and port with it's assigned ip address from the ISP and a different port. Thus, your router funnels everything to the internet from the private side through the IP address assigned by the ISP (it makes many home ip addresses look like one internet ip with lots of ports). It uses different ports (no problem there) so when the replies come back to it, it can translate it back to the address it assigned to your computer and use the port your computer made the request with. It will most likely have a static address of 192.168.0.1 on the home side. Your home computer needs to use this address for it's DNS resolution as well as the default gateway.

If you are using XP or 2000, go to a dos prompt on the computer and type IPCONFIG /ALL

The response should tell you the ip address assigned to your computer, the DNS it's using, and the default gateway. Your computer should have an address in the range listed above, and use the router's fixed address on the home side for the DNS and gateway. Everything should work as long as the NAT is functioning properly on the router.

You can also use IPCONFIG /RENEW if needed to renew your ip address with the router if you leave your computer on for extended periods of time (more than a day).

 

[ReddLefty]

I agree with both Jim and Rico, but I also wanted to add the point that you MUST restart your cable modem box if you change anything related to the MAC address in the router.





"In space, nobody can hear you click..."

 

[kev01]

First of all, thanks for your quick replies,

hi Jim..yep, my ISP might have registered the MAC address of my NIC. By this, do you mean the MAC address of my broadband modem? As I said, i have used different PCs (thus different MAC address) to connect to the net..and it works fine. How do I change the MAC address of the WAN side of my NETGEAR router to the MAC address that is registered with your ISP??

hi Seapray..yep, the IP of my router as u said is 192.168.0.1 - I have configured my computer with the DNS server of my ISPs...i will try as u said to configure it with my router IP (192.168.0.1) - hope it will work

thanks,
kev

 

[jfwebber]

I have not configured alot of NETGEAR routers, but there should be a page that states something similar to the following:

Router's Mac Address
Use Default Address
Use This MAC Address

You should check the radio button that states Use This MAC Address which will be the MAC address of the ethernet card in your modem.

I would then power cycle your modem and router and you should be all set.

Jim

Jim Webber
Network Administrator MCSE CNA

 

[kev01]

thanks Jim,

I used to MAC address of the ethernet card of my modem and it now works!

cheers!