IP address "is it permanent"

[curiousone]

I just started reading the articles and I read on one of them that you could block a user to this forum by knowing their IP address.
Here my question then. Many users connect to the internet whereby thier ISP assigns them an IP address. I understood that the IP address is different each time. Hence if this is the case how would you block the user.
By the way how do I find out my IP address in the first place.?

Thanks in advance.

[YODA74]

Welcome toPC Guide,curiousone: as far as i know your ISP.assine's you an address,this address does not change it stays the same this is how they can track your computer you can how ever change your home page.but the numbers on your computer from your ISP stay the same.You can not block some one from the internet (your self) at least not that i know of i beleive only a web provider can do this .By the way why would you ask a question like this (if you don't mind me asking sounds real suspicious?). http://www.PCGuide.com/ubb/smile.gif

[curiousone]

Thanks for the rapid reply. The reason I ask is out of curiosity.If someone know your IP address then surely it is possible for them to log profiles of a user (like cookies do I think). It sound like I've read Big Brother once too often. But I have been asked this question before and never had an answer to give. Anyhow back to the subject.
My understanding of IP address's it that the ISP server assigns it. I have that setting in Dail up networking, and my ISP didnt tell me to put some IP address in.

[YODA74]

do you have a home page like i'm on cable my home page is roadrunner when i click on internet explorer and bring up my home page in the address bar is my IP know what numbers they assine to the com puter i do not know that would be on there server and i don't think they will give that info for security resons. Hope this helps you. http://www.PCGuide.com/ubb/biggrin.gif

[pjungwirth]

To determine your IP address under DOS, type ipconfig at a DOS prompt.

Computers on the Internet can have static or dynamic IP addresses. Home users connecting through an ISP generally have a dynamic IP address. (Try typing ipconfig before and after connecting through your ISP.) Often, computers on an internal LAN are also assigned IP addresses dynamically. The most common protocol for this is DHCP. When a computer gets on the network, it sends out a packet asking to receive an IP address. A DHCP server maintains a list of available IPs and tells the computer which one to use.

(A question for the masters: does a PPP connection negotiation include IP assignment, or does this happen afterwards through DHCP?)

On the other hand, computers that are permanently connected to the Internet generally have a static IP address. They have to, otherwise you couldn't reliably map their domain name to their IP address. Originally, every computer on the Internet had a static IP address, but dynamic IP addresses have helped mitigate the problem of IP shortages and also provide extra security by making computers "private."

Three ranges of IP addresses were set aside, never to be used on the Internet. These are 10.0.0.0 to 10.255.255.255, 192.168.0.0 to 192.168.255.255, and 172.16.0.0 to 172.31.255.255. Paradoxically, more computers on the Internet use these numbers than any others! When you type ipconfig, you'll probably see a number in one of these ranges.

What's going on is that these numbers are reserved for a LAN that is connected to the Internet only through a special server running Network Address Translation (NAT). That server has a static IP address facing the Internet, which it shares with all the computers on the LAN. It sends packets outbound packets as if from itself, and it forwards inbound packets to the right internal computer. That way, you can have a whole network and only use one static IP address. This is also more secure because the internal computers are more or less invisible to the outside world.

NAT and dynamic IP addresses aren't always used in conjunction, but they most often are. (You could, for instance, have a static-but-private 192.168.42.42 address or a dynamic-but-public 34.56.3.8 address; it's just less common.)

Sorry if this is way more information that you wanted. I guess I got carried away. To answer your original question, you're right that it would be difficult to block a user based on an IP address, because that IP address would change with each connection. You'd have to block a whole range of IP addresses. And what if the user happened to be on Earthlink??

Paul
~{:-)

[rond36]

If you connect via DSL, ISDN, Cable, T1, or T3 Internet connection you usually have a static IP address assigned by your ISP(always the same IP)
If you connect via dialup connection most times you have a dynamic IP.
your IP is assigned by a DCHP server every time you connect and most of the time it wont be the same as the one from a previous connection.
if you want to find out what your IP address is go to start-->run type in winipcfg.exe or browse to your windows folder and click on winipcfg.exe
be sure to select the correct connection device.

[curiousone]

Thanks Paul. I tried the Ipconfig from Dos and got it. I understood most of your reply http://www.PCGuide.com/ubb/wink.gif. I guess the bottom line is that you can only block a group of IP addresses, so if you blocked the last 3 digits of the IP address does that mean you block out 999 users?
By the way this forum has a logged IP on each message. Pressumably this is to trace a user back to an ISP, so can the ISP then tell who the user is?

[Gallaeglagh]

I'm not fully sure how webmasters block certain users but in general your ip address will fall into a certain range. Then peicing together other easily obtained information about you (see http://www.securitywriters.org/texts/internet%20security/anonymity.html )
you get red flagged.

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[Paleo Pete]

The IP depends on the type of Internet connection, as described above. Standard modem connections usually get a different IP assigned by the ISP each time they connect. If you didn't have to input an IP Address to set up your connection, you most likely have that type. winipcfg is the windows version of the DOS ipconfig utility, and will give you your current IP address, when typed into the Run box.

The IP logging used on the forums logs whatever IP address is assigned to your computer at the time you post your message. That could, if necessary, be used to find out who a particular person is, but I seriously doubt if the ISP would release a person's identity to Charles or myself without VERY good reason. Most ISP's are very particular about the confidentiality of their user's identities. Normally the only use we would have for a person's IP Address would be in the case of someone being a major nuisance, then we could contact the ISP with the IP address, report the problem, and the ISP would then be able to find out who was responsible, and take appropriate measures.

The IP address is not what is used to block users from the forums, in the rare occasions it becomes necessary, the username and password are disabled when we determine that a user should not be allowed to post further messages. To my knowledge that has only happened 2 or 3 times in my year of participating here, which I think is an excellent record. Usually a warning is sufficient.

By the way, only forum administrators, Charles and myself, are able to retrieve users' IP Addresses. That's for your own protection.

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[Pyro]

Originally posted by curiousone:

By the way how do I find out my IP address in the first place.?



You can try typing "winipcfg" under Start->Run. A wealth of information including your IP address, DNS Server, Gateway Address etc will be displayed.

As far as I know, if you're accessing the Internet through a cable or DSL modem, your IP address is always fixed by the ISP. If you're logging through a dial-up account (i.e. 56k modem), due to the limited number of IP addresses in the world, a distinct address is dynamically assigned to you everytime you log on.

[Ghost_Hacker]

does a PPP connection negotiation include IP assignment, or does this happen afterwards through DHCP? Here's some information that might help answer that question.


"The RAS server records the address of the DHCP server, the leased IP address,
when the lease was obtained, when the lease expires, and the lease length. All
other DHCP options defined for that scope are discarded. When the client dials
into the RAS server and requests an IP address ("Server Assigned IP Address" is
selected) the RAS server will use one of these cached leases. The IP address is
then given to the dial-in client, which is unaware that the IP address has been
obtained through DHCP. The RAS server maintains the lease on behalf of the
client. Therefore, the only information that the client receives from the DHCP
lease is the IP address.":

Hope that helps http://www.PCGuide.com/ubb/smile.gif


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