unable to change lan card ip address

[mandalx]

I am a computer geek, but not an IT professional. Sorry for posting this question here, but I couldn't find the relevant answer on the internet.

My home PC has on-board LAN (built-in to motherboard), runs WinXP , and connects to internet via ADSL modem.

The ADSL requires dial-up, with account name & password, and is then assigned an IP address from the ISP. The moment i switch on the modem it logs in by itself.

The PC itself (ethernet card) receives an internal IP address (169.254.etc) from God-knows-where.

The problem: While surfing the internet is fine, but local software cannot initiate communication with outside internet that requires local software to announce its IP. Reason: when the local software announces its IP, it announces the private IP address. When the other party tries to lookup this IP address on the internet, it finds nothing.

Specific example:
1. Although I can do MSN text chat, I cannot start a MSN voice chat invite; it simply doesn't work. Whereas if someone else invites me for MSN voice chat, this works.
2. For networked gaming over TCP/IP (e.g. Diablo, Age of Empire, etc), I cannot host games, as other players cannot join my game. --> If they enter the IP address for my ethernet card, they cannot find the game. If they enter the IP address for my DSL modem, my DSL modem doesn't know a game is being hosted by the PC, so doesn't respond.

How do I get around this problem?
Thanks.

[Ob1]

The PC itself (ethernet card) receives an internal IP address (169.254.etc) from God-knows-where.


this is a default ip address that windows assigns when it cant obtain an ipaddress from a dhcp server

[mandalx]

well the IP the lan card is assigned is static and get's it from the modem

[Ob1]

is your broadband service providing you with a static ip address, or are you paying for a static ip address? most residential service is set up for dhcp. if its set to dhcp change your lan card settings to obtain ip address automatically.

[mandalx]

Originally Posted by Ob1 is your broadband service providing you with a static ip address, or are you paying for a static ip address? most residential service is set up for dhcp. if its set to dhcp change your lan card settings to obtain ip address automatically.

first of all thank u very much for the comments. Actually my ISP provides dynamic IP to the modem every time i connect the ADSL modem then the modem further assigns static IP to the PC which is something like 198...2.
I donot understand what is DHCP.
in my ADSL modem "lan configuration", which i access by 198....1, it says use static IP and is the same IP which gets displayed in the PC when i type ipconfig & is like 198...2. and the most frustrating part is i am not able to change LAN configuration of the ADSL modem.
there is a option of obtain IP automatically in the modem Lan configuration but the modem hangs once i use this setting and ican not change the any setings here
in my lan card configuration the setting is to obtain IP automatically
please help

[mandalx]

first of all thank u very much for the comments. Actually my ISP provides dynamic IP to the modem every time i connect the ADSL modem then the modem further assigns static IP to the PC which is something like 198...2.
I donot understand what is DHCP.
in my ADSL modem "lan configuration", which i access by 198....1, it says use static IP and is the same IP which gets displayed in the PC when i type ipconfig & is like 198...2. and the most frustrating part is i am not able to change LAN configuration of the ADSL modem.
there is a option of obtain IP automatically in the modem Lan configuration but the modem hangs once i use this setting and ican not change the any setings here
in my lan card configuration the setting is to obtain IP automatically
please help

[Reaper]

Well in not sure ive read this thread right,,but i belive Obi to be right,,In your connection properties/ TCP/IP properties /Advanced / tabs,,Do u see DHCP Enabled" under the ip address heading?

[Ob1]

do you have a router that is connected to your modem? ie:Linksys, netgear, dlink?
the connection would look like this: modem > router > computer
DHCP is when your ip is automatically assigned. what happens is they provide you an ip address for a specified amount of time called a lease, now when that lease expires what usually happens is your pc automatically requests another ip address. most of the time you pull the same ip address, but there is no guarantee that you will. so your ip address is always changing. these 3 terms can be used interchangably: (dynamic, automatic, DHCP)

your modem doesnt usually assign a static ip when the service you are paying for automatically give you an ip address (DHCP). the static ip address would be given to you by the isp, and they cost more (usually find them on commercial accounts). to me it sounds like you might have a router, and the router is obtaining the Dynamic ip address from your isp. now your router is also in charge of handing out internal network ip addresses, usually in the range of 192.168.1.xxx there are other private ip ranges to use as well, but you can assign your pc a static ip address of 192.168.1.xxx by going into the properties of your network card adapter, and instead of having it obtain an ip address automatically, you would click the bullet to select "use the following ip address" and in there you would specify the ip address, subnet, default gateway.

have you contacted your ISP tech support to ask them about the modem and how it is suppose to be configured?

im not to familar with adsl modems because i have always used cable modem service, so if im wrong in assuming what i wrote above i hope somebody can correct me.

[Reaper]

Could TCP/IP Filtering be an issue,?,,with his limited connectability problems? Permit all-

[mandalx]

well the modem perhaps itself is behaving as router as it assign 192.168.1.2 as the IP address always to the lan card and it receives a different IP always
the configuration is modem > computer
the hardwired connection is RJ11 from wall socket to a splitter which seperates the voice and data frequencies, then there is Again a RJ11 cable from the splitter to the modem and then from the modem there is RJ45 lan cable to the PC.
in order to configure the modem 192.168.1.1 has to be typed in the explorer
and it opens a login page then after logging in we can make changes
i have looked in to the settings and the DHCP is enabled in the lan card settings and the modem settings as well
the protocol used is PPOE
http://www.calcutta.bsnl.co.in/dataoneinstall
have look at the site it clear the picture a little more
i am using the UTstar 300 r2 modem

[glc]

Okay, I see what you are getting at. Your modem is actually acting as a router. It's using network address translation (NAT). To do what you want, you have to be able to forward ports in the modem (router) to the private IP address of your machine (192.168.x.x) for a lot of applications to work.

The easiest thing to do, but this is a security risk, is to find out how to bypass the PPPoE and NAT in the modem, turning it into a simple "bridge" modem. Then you would use the builtin PPPoE client in XP to set it up like a dialup connection. Otherwise, you need to find out how to forward ports, and which ports need to be forwarded.