What is meant by “dynamic” and “static” IP (Internet Protocol) address?

Question

Dear Yahoo! Friends,
Please explain to me the difference between a “dynamic” IP address and a “static” IP address. I am using a Dial-Up Internet Connection through a landline telephone for accessing the Internet. My ISP said I am allotted a “dynamic” IP address. What does it mean? Which IP address is better to have? What are the advantages and disadvantages of each of them? Why should one have an IP address at all? Please enlighten me on this subject.
Thanks and regards,
M. Seetha Lakshmi

Answer 1

A static IP address belongs specifically to a single computer. Dynamic IP is assigned when you log on to a network, and released after a period of time or when you log off the network.

Answer 2

Every computer on the internet must have an IP address. IP address is a unique idenitty for a computer. Without a way to uniquely identify each computer on the internet it won't be possible to send the correct data to correct computer.

Whenever you dial-up and connect to your ISP network, your computer is assigned an IP address from a pool of IP addresses that your ISP has set aside for dynamic IP address assignment. When an IP address is assigned in such a way from the pool, it is marked as 'in use' and won't be reused again until it is 'released'. When you disconnect (hang up) your connection, the IP address assigned to your computer is marked again as 'release' or available and it can be assigned to the next user who connects to the network. For most client computers (the computers used in home where you only use browser, IM or other internet applications on a desktop PC), dynamic IP address is all that is required.

If on the other hand you are running a server (like a Web Server for example) you need a static IP address. Static IP addresses are usually assigned by ISPs where the connection always stays on (you don't have to disconnect). In such cases the IP address of the computer will never change.

If you are a consumer using internet to browse web pages and use IM, a dynamic IP address is all you'll ever need. Don't worry about the dynamic IP address, it is automatically taken care of by your ISP when you connect (no matter you are using a dial-up or a broadband connection.)

Answer 3

Short version: dynamic IP changes every time you access it. You dial in today, you get one IP address. If you dial in tomorrow, you will get a different address.

Whereas static IP is.. well, static. It doesn't change. You always get the same IP address.

Your IP address is, well, you. Without an IP address, nobody can reach you on the Internet. When you download your mail, your mail program connects with the mail server, and says "send mail to my IP address". Clearly, without an IP address, you won't get anywhere. Same with every sort of Internet connectivity.

As for which is "better"? As a regular user there is no difference to you. Your ISP provides dynamic address because it is cheaper for them to use a limited number of IP address for all the subscribers, since not everybody will be online at the same time. Thus, the ISP can just allot say, 32000 IP addresses, when it reality it may have several times that number of subscribers.

A professional user who needs an always-on connection, such as someone running a server, will need a static IP. Web servers, for example, need static IP, or else you won't know where to go each and every time! (It's POSSIBLE to use dynamic IP to host website, but that's another story altogether, and will take much longer to explain). And those cost a lot more, as it's considered an dedicated connection.

Answer 4

A static IP address is one that never changes. It is programmed into your computer, and your computer will always have that address. Since you permanently have this address, no one else can use it when you are online, and since it can be difficult to know when a certain person is online, each computer in a network needs a different IP address. This tends to be a very inefficient use of IP addresses(which believe it or not are a scarce resource). The advantage to this scheme however is that if you always need to access the same computer, you always know exactly what it's address is. Static IP adresses are mainly used for Servers since you always need to know what a server's address is in order to access it.

Dynamic IP (Also called DHCP sometimes) is a scheme where when a user comes online, they are given an IP address by their service provider or router. When they go offline, that IP address is freed up so that another person can use it. This makes it difficult for people to consistently find the same computer(since their address changes everytime they log on). This is a very efficient use of IP addresses and can actually deter hacking(as hackers rely on being able to access the same computer multiple times).

Dynamic IP addresses have the added benefit of an easier set up process, and easier administration, and so are used by most ISPs.

Answer 5

Your IP address is basically your passkey to the internet. Everybody gets one.

Dynamic means that your ISP has a pool of IP addresses, and every time you connect you may or may not get the same one. This means more to the ISP than it does to you.

Static means an IP address (and other informaion) is assigned to you and never changes. This is really only useful for people who have services that point back to them. For example, if you have an e-mail server or web server running out of your house that other people would get to.

If you are only on a Dial-Up connection a static IP would most likely not be very useful to you because of the speed and that fact that the connection is not always on, so having services point back to you wouldn't work.

Answer 6

Static is constant, or always the same i.p. address, and dynamic is changing, never the same. Usually, to have a static IP it would cost more per month through your isp. Static IPs are used alot for connecting to the office from home, of office to office through a vpn. An I.P. address identifies each computer to the internet. The typical home pc, especially using dial up, does not require a static ip.

Answer 7

Dynamic IP- A non-permanent IP address automatically assigned to a host by a DHCP server.
Static IP - An IP address which is the same every time you log on to the Internet.

Answer 8

IP address is like your home address for recieving mail. without it, you can not connect to internet. if you using dial-up, a server form your ISP grant you an IP adress automatically , so you can go to Yahoo.com for instance.
Static IP address means that an Administrator of a local network give you an specific Address.
you can find your ip address in www.whatismyipaddress.com

Answer 9

If you want a static IP your ISP will give you one but you have to pay for it.