IP changing?

I was wandering if its possible that an attacker can change your ip? My friend that I built a computer for boots his comp. up one day and he couldnt connect to the internet,Now I tried everything under the sun to fix it. It finally came to wiping the harddrive reinstalling winxp. And it still would not connect? I was dumbfounded.So two days later he calls me and tells me that he had called comcrap(comcast)and they run the ipconfig.exe and that fixed it.

now he is running a hub that feeds internet to his computer and another old one that is running win98se and as far as I know there is no security for the hub itself if there is even a need for it I dont know anything about hubs(and I know he needs a firewall)...But it seems to be like a router and I know that routers are frequently
attacked in an easy manner, I have no idea how but anyway thought I would get possible answers here what do you guys think?? :confused:

As far as i know he could't change your IP...you could also tell us what ISP he is running and what connection...DSL ips change every time with a restart...so does cable i think but am not sure. For DSL its certain, but i dont really understand what the problem was...he couldnt connect to the internet because of his ip? wtf lol

Yea I guess , I tried to reinstall ie before wiping drive but it did nothing.when I tried to access windows restore it would not let me in and gave a error like "win32 dll library not accessable" or something. the isp is comcast and its cable. keep in mind im not computer expert
I have done 12-volt electronics my whole life and messing around with computers for about 5 years.he has antivirus and we scanned the system but thats not to say that it wasnt a virus so I dont I guess its not that important becuase its fixed ... just real strange

He just opened ie one day it wouldnt connect. I tried everything I could think of like lan settings in the options menu. Detect network settings.connection wizard, and I forgot to tell you that the other computer thats on the hub was still connecting the whole time. We even tried to use the port and ethernet card from old computer .Not until he ran ipconfig.exe it then fixed whatever was wrong ,Im a lamer what can I say......

Quote:

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We even tried to use the port and ethernet card from old computer

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uh, do you think it's possible that this was changing the ip ? ;)

Er... are you sure he just didn't have the wrong settings on his router/hub/switch/whatever? Maybe the dhcp thing wasn't working, or he had a private IP instead of a internal network one? Or if he doesn't have a router or something like that, maybe he moved the eth card into another slot, and the MAC addy changed, there are some ISPs that record the MAC addy, and use it to give the user an IP.

Peace

MB

Hi Everyone

I am having a similar kind of problem, Everytime when I want to check mail (outlook express, win98se) the server pop settings and smtp settings change to 127.0.0.1. I have to change to my settings to pop.net4india.com and smtp.net4india.com which is the original. There are 2 more computers connected through the browsegate proxy server for internet access. I am using zonealarm for firewall.

What could be the reason.

Thanks

pZargs, it's possible that they ran "ipconfig /release" . Some ISP's have a preset life for an IP address. After this is over, you must obtain a new one.

Cheers,
cgkanchi

PS: As, MB said, check your DHCP settings.

:confused:
Can you be a little more specific about "running ipconfig, and it fixed it"?

Was it ?
> ipconfig
> ipconfig /all
> ipconfig /renew
> ipconfig /renew {card}*
> ipconfig /release {card}

What is the message that comes back when you run > ipconfig ? -- that will tell us a lot.

...and, I apologize for the obvious questions: this card worked in another system? Cable OK? etc., basic trouble shooting...

I have had cards that were physically bad that would occassionally dump the TCP/IP stack and/or just randomly work/not work.

<quote>
pZargs, it's possible that they ran "ipconfig /release" . Some ISP's have a preset life for an IP address. After this is over, you must obtain a new one.
</quote>
well if they (isp) did run "ipconfig/release" then they must have changed the ip address of all the hosts ,isn't it ? which means all the hosts have to be disconected to the same period of time . quite unlikely !!

With Comcast all you need to do to change your IP is to unplug your cable modem for 2 min and after you reconnect they assign you a new IP. If I had to bet during the "ip config" they (concast) had him unplug his cable modem. Then they had him restart his computer.

Regards
-Breeze

Ummm.... tejaswyappalla, ever heard of DHCP?

Cheers,
cgkanchi

What it sounds like is that he is using a router of some type, most likely something small for home use like a 4 port linksys. what you want to do is make sure the nic is set to obtain an ip address automatically. If it is and he still cannot connect try this:

1.) go to start > run > and type cmd
2.) at the prompt type ipconfig /all
you will get something like this

Windows IP Configuration

Host Name . . . . . . . . . . . . : computername
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection 4:

Connection-specific DNS Suffix . : yourisp.com
Description . . . . . . . . . . . : Intel 8255x-based PCI Ethernet Adapter (10/100) #2
Physical Address. . . . . . . . . : 00-80-29
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 169.254.....
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . :
DHCP Server . . . . . . . . . . . :
DNS Servers . . . . . . . . . . . :
3.) if you ip is 169.254.....
type
ipconfig /release
ipconfig / flshdns

4.) then go to your nic card setings in local area connection and uninstall tcp/ip for your nic
5.) reboot and reinstall tcp/ip
6.) shutdown the computer / router / cablemodem
7.) turn on cable modem first and let it light up all the way
8.) turn on router and wait 1 min.
9.) boot up computer and repeat step 2
10.) check your ip and see if it is something like 192.168.1.100
if it is you should be able to connect
if not check for conflicts in device manager such as irq / also make sure it is properly installed under network adapters

Ok all some of you are right on the money we found out that it was just wrong configuration, although I still dont understand how it became that way?He and I both play on-line games like counterstrike,tfc,half-life,starwars galaxies, dont know if anyone is able to mess around with his settings when we are connected to those games? but installing norton firewall this weekend so that should stop any direct attacks then we'll just wait and see if it happens agian.thanks alot to all of you for replies everbit helps...... :D