Explain IP Address?
An IP Address is a unique number used to identify a computer or a network device in the network or on the Internet. An IP Address looks like the following,xxx.xxx.xxx.xxx where x is a decimal representation of the equivalent Hexadecimal value. As you can see, there are 4 Octets split by three DOTS. This way of representing an IP address is called DOT Notation. An IP Address comprises of 2 parts. A Network ID and a Host ID. In simple words, its like the Street Address and the Door Number, where Street Address is your Network ID and the Door number is the unique host ID. Top
How come the systems know to differentiate between Network ID and the HOST ID?
Well, that's where there comes in a new component called Subnet Mask which allows systems to differentiate between Host ID and the Network ID. Top
What is a Subnet mask?
A Subnet Mask is an address mask that allows, systems to differentiate between the Network ID from that that of the Host Ids in a IP Address. This is represented very much as how an Ip address is represented. Top
What is IPV6?
As the Internet is flooded with more and more networks and computers, the system is now slowly running out of available addresses to fit in more networks or computers. For this reason, IPV6 is being designed. This is a new version of the IP protocol addressing method (V6 is Version 6) which is to slowly and steadily replace the existing IPV4 (V4 is version 4). Top
What is Default Gateway?
A Default Gateway is an address to which all the packets to which there is no known Route is available is been sent. In otherwords, if the system doesn't know where to send a set of packets, it will forward it to this address which then takes care of routing to appropriate destinations. Top
What is a Connection Gateway?
A connection Gateway is very much like a Default Gateway except for the fact that this address is the one where any packets that needs to be sent out on the Internet is been routed to. In other words, this is the address that communicates on the Internet and hence known to the Internet. Top
How will I know my IP Address?
Every Operating System has its own way of showing the IP Address. In windows, 1. Click Start – Programs – Accessories – Command Prompt. 2. Type ipconfig and press Enter. This will show the IP Address, Subnet Mask and the Default Gateway. For detailed information, type ipconfig /all and press Enter. In Unix/Linux/Solaris Open a Terminal window and type ifconfig. NOTE: This requires you to have sufficient priviledges to execute the command. Top
My IP address shown on www.itsyourip.com is different from ipconfig / ifconfig information. What is wrong?
Nothing is wrong, but the difference is as explained in connection gateway, this is the IP Address with which you are identified on the Internet. This is likely a case, wherein you have Internet Connection Sharing is setup or a Home Networking is setup in your home or there is a routing device which is more a case with most of the Broadband users where you have an internal IP Address assigned to your computer by the Routing device and it has an external IP Address (assigned by ISP) with which it talks to the internet. These are called Private an Public IP Addresses. Top
What is a Private IP Address?
A private IP Address is the one, which is not recognised on the Internet. This is mostly used to connect different devices locally on a small network or even in huge networks. These devices cannot directly participate on the Internet for the simple reason that they are recognised. This is where devices like Router comes into picture where it translates all the packets from these Private devices into the Public IP Addresses that is being assigned and forwards to the Internet and exactly does the reverse for the incoming packets on the Public IP to give it back to the private devices. This process of translation is called Network Address Translation and the process of forwarding packets from various different networks to different other networks is called Routing. Top
Is there a list of Private Addresses?
Yes, there is one as follows: (10.0.0.0/8) – 10.0.0.0 to 10.255.255.255 172.16.0.0 to 172.31.255.255 18.104.22.168./16: 192.168.0.0. to 192.168.255.255 Top
What is a Loopback Address?
A loopback address is the one, which normally used internally by the system to point to itself. This is different from another Public or Private IP Address. This is mostly used to call the local system and for troubleshooting purposes. The default Loopback IP Address is 127.0.0.1 Top
How do I know which is Private IP Address and which is Public IP Address?
Well, there is no actual difference between these addresses except for the fact that a set of address are reserved for private use and can be used by anyone to use locally on their network. Unlike, the Public IP Address are assigned by your ISP and normally comes at a cost (Home users may not pay for this but are hidden in your Internet charges). Additional Public Address can be purchased, in other words, leased from the ISP's to host servers of your own on the Internet. Top
What is Public IP?
On the other hand, Public IP is the face of any network device or a computer on the Internet. This address is the valid address normally assigned by your Internet Service Provider to your network or your computer. Top
How will my computer get its IP Address?
There are 2 ways that any Network device will get its IP Address. One is manual entry by users / administrators while the other is automatic called DHCP. A DHCP server in the network (locally) or at your ISP (Public) does this job. Normally, most if not all computers and network devices are setup to look for a DHCP server and obtain IP Address. Top
What is DNS?
In simplest terms, DNS is a Domain Name Service which translates the meaningful addresses like www.google.com into computer aware IP Addresses. Remembering all the IP Addressess of various available websites, resources etc., will mean Internet is a place what it wouldn't as it is today. Hence, a meaningful representation to these IP Address is required and hence the concept of DNS. When you type www.google.com in your browser and press enter. This is sent to the DNS server which translates this into a valid IP Address and tells the browser to where to go next. More detailed info available at DNS section. Click here to take you to DNS. Top
What is a Firewall?
In Simple words, A firewall is as much as the huge walls of a Fort to block enemies coming into the territory. These are devices or Software which deny access to your computer from anything external. It stops hackers, intruders and other malicious evils from accessing your computer and take any critical information like Bank Account Detials, Credit Card details, Identification Information or even your Business critical information. It is highly advisable to have a Firewall device or a simple software loaded on your computer from these evils. Apart from using firewall, one has to ensure that a proper antivirus software / mantispyware software is installed and properly run on the computers to ensure absolute security on the Internet, failing which you always vulnerable to attacks from the Internet.
What is a IPID?
The IPID is the Identification field of the IP protocol packet header which a;long with the source address uniquely identifies the packet. The IPID is used to reassemble the packet should it be fragmented. Every fragement of the packet will then have the same IPID for the destination device identify them all to be a simgle packet.
The IPID is primarily used in the Idle Port Scanning by a hacker where he spoofs a victims IP address to then use it to scan a target network or system. Various Operating Systems generate these IPIDs in different ways.