If you aren't sure what IP address is, IP (Internet Protocol) address is a unique address that identifies a computer or a device on the Internet. It contains 32 bits or 4 bytes (octets) and is written in four sets of decimal numbers separated by a period (or dot) in between. Each set of decimal numbers represents a byte (i.e. 8 bits) and can not exceed 255, that is when all the eight bits are 1 (or 11111111). Example of IP address: 202.60.80.1

An IP address is comparable to a telephone number that uniquely identifies an individual or a business on the telephone network.

The anatomy of IP address

Every computer or device on the Internet is part of a network (e.g. ISP, corporate, or home network). That's why IP address body (i.e. xxx.xxx.xxx.xxx where x is a decimal number) consists of network identity (ID) and host (i.e. node/device) ID. A subnet mask value which resembles an IP address is usually given along with an IP address to help identify which part of the address refers to network ID or host ID. Subnet is logical grouping of hosts in a network that functions to segregate traffic.

In a class A IP address, the first byte refers to network ID and the last three bytes refer to host ID. In a class B IP address, the first two bytes refer to network ID and the last two bytes refer to host ID. In class C IP address, the first three bytes refer to network ID and the last byte refers to host ID. Class A IP addresses are used by very big networks, class B by medium to large networks, while class C by small networks.

Example, if your computer IP address is 192.168.1.3 (a class C IP address), it must belong to a network (LAN) with this network address 192.168.1.0 and its host ID is 3.

Dynamic IP address vs. static IP address

When your computer logs on to your ISP, your ISP assigns an IP address to it. In the case of dial-up access, your computer will get a different IP address each time it logs on to the ISP and makes an Internet connection. That is called dynamic IP address. On the other hand, using always-on connection such as DSL or cable modem, your computer is usually given the same IP address all the time by the ISP. That is called static IP address.

Dynamic IP address can also be assigned to your computer by a broadband router (or residential gateway) if your computer accesses the Internet through it. Dynamic IP address assignment is handled by a DHCP server at your ISP or built in a residential gateway. To ensure security during an Internet connection, newer DHCP server can change the IP address regularly at a predefined interval.

Private IP address vs. public IP address

Private IP address is only used within a LAN or an internal network (e.g. home or company network), while public IP address is used for communication over the Internet. If your computer is part of a company network, chances are it was assigned a private IP address and when it connects to the Internet the private IP address is translated to a public IP address by a router which has NAT capability. Private IP address is also known as internal or LAN IP address, while public IP address is external or WAN IP address.

OK, in case you are wondering, the table below tells you which IP addresses are allocated for use only in internal networks as private IP addresses.

What is The Function of IP Address?

IP addresses are used by devices called routers on the Internet to forward messages from one computer to another over the Internet. In comparison to the telephone network, a router acts like a telephone switch (exchange) that connects a caller to the dialed phone number.

When you send a message over the Internet, the message is broken down into small pieces - called packets - where each packet can take its own route. IP addresses information is included in the packet header. Your computer sends each packet along with your computer (i.e. source) IP address and the receiving computer (i.e. destination) IP address. The routers read the source and the destination IP addresses by examining a packet header and forward the packet accordingly.

However, you usually type a web address (e.g. www.channel-11.net) instead of an IP address in your browser's address bar. That's because there are servers on the Internet that store the mapping of web addresses to IP addresses. They are called DNS servers. The DNS servers handle the translation from a web address to an IP address. A DNS server is analogous to a telephone directory that contains a list of telephone numbers and businesses or individuals who own the numbers.

How many routers do forward my message before arriving at a specific web address?

Your message does not get to the destination address via one router. There are many routers involved in forwarding your message to the destination computer (i.e. in this case, a web server). You can do little investigation by typing tracert ip_address or tracert web_address in Command Prompt. Replace the ip_address or web_address part after tracert with your destination, e.g. www.myexampledestination.com. This command will trace the route that takes your message to its destination by sending ICMP messages. Some routers aren't allowed by their firewalls to accept an ICMP message, but since many allow it, by reading the result you would be amazed at how far your message can travel in milliseconds and how many hops it makes to get to its destination.

How will the website I visit use my IP address?

Your IP address can be used for location targeting that is identifying where you come from and presenting you relevant content tied to your geographic location. That's because IP addresses in bulk are allocated to regions and countries around the world by the IANA in a delegated manner through several Regional Internet Registries. And each ISP obtains IP addresses for its subscribers from Local or National Internet Registry.

Nonetheless, a website you visit can not know who you are, solely from your IP address. Unless you register to the website and gives it your personal information, you will remain anonymous.

Is there a risk from exposing my IP address to the world during an Internet connection?

As in the real world, the virtual world also has bad people who always try to find holes to gain access to Internet users' computers to distribute virus, spam, adware, spyware, malware, to make them little agents for starting an attack to a big company's server, or to steal their user names, passwords, and credit cards details. In fact, the potential attackers don't rely only on IP addresses information to find their targets, they can use e-mail, website's active element, file sharing and other client-side applications to cause damage or identify personal information.

Fortunately, you can protect your computer using firewall, antivirus and anti spyware. Those tools usually have been integrated into e-mail clients, Internet browsers and Operating Systems (OS). But to stay safe, your software must be always up to date. Be sure to update your protection software and your PC's OS regularly. Software updates are usually provided by the software vendors periodically or when there is a new kind of threat.

In this regard, using dynamic IP address instead of static IP address gives an advantage in that your computer becomes a moving target that is harder to attack rather than the fixed targets that use static IP addresses.

How can I hide my IP address?

If you access the Internet through a proxy server, it's the proxy's IP address that is seen by the website you visit and other parties who silently monitor your Internet session. However, your identity is still known to the proxy server.

If your computer connects to the Internet through a broadband router (or residential gateway), your computer IP address is hidden from the Internet because your router's IP address represents you on the Internet. However, your identity is still known to your ISP who assigns an IP address to your router.

What is IP address version 6 and what is it for?

The 32-bit IP address described above is IP version 4 (IPv4) address. IP version 6 (IPv6) address is 128 bits (16 bytes) long, that's 4 times longer than IPv4 address. IPv6 address is written in eight pairs of hexadecimal numbers separated by a colon in between. Each pair of hexadecimal numbers represents a byte. Example: D1E5:0020:11F0:0E01:13B3:80A2:A3C1:3B1D

IPv6 was originally meant to increase the number of available IP addresses from 232 (that's more than 4 billion) to 2128 (use your calculator !) to anticipate the exponential growth in the number of computers and devices that will be connected to the Internet. Later on, IP version 6 is intended to provide QoS support over the Internet and introduce improvement in routing, security, and network configuration. Many new networking products support both IPv4 and IPv6 to take advantage of IPv6's strength while maintaining support for the predominantly IPv4 networks.

Source : conniq.com