Questions tagged [ip-address]

IP address is a numerical label assigned to each device participating in a computer network that uses IP for communication.

An Internet Protocol address (IP address) is a numerical label assigned to each device (e.g., computer, printer) participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing. Its role has been characterized as follows: "A name indicates what we seek. An address indicates where it is. A route indicates how to get there."

The designers of the Internet Protocol defined an IP address as a 32-bit number1 and this system, known as Internet Protocol Version 4 (IPv4), is still in use today. However, due to the enormous growth of the Internet and the predicted depletion of available addresses, a new addressing system (IPv6), using 128 bits for the address, was developed in 1995,[3] standardized as RFC 2460 in 1998,[4] and its deployment has been ongoing since the mid-2000s.

IP addresses are binary numbers, but they are usually stored in text files and displayed in human-readable notations, such as 172.16.254.1 (for IPv4), and 2001:db8:0:1234:0:567:8:1 (for IPv6).

The Internet Assigned Numbers Authority (IANA) manages the IP address space allocations globally and delegates five regional Internet registries (RIRs) to allocate IP address blocks to local Internet registries (Internet service providers) and other entities.

Source: Wikipedia.

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586 questions
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Use first or last free IP for the default gateway?

Please assume a simple LAN on 192.168.100.0/24. Would you configure the default router on 192.168.100.1 or 192.168.100.254 and why? Thanks
Thomas
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Finding out if an IP address is static or dynamic?

I run a large bulletin board and I get spammers every now and again. My moderation team does a good job filtering them out but every time I IP ban them they seem to come back (I'm pretty sure it's the same person on some occasions, as the post…
Joshua
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are github`s IP Addresses changed?

I had an issue today where my deployment on my application servers couldn't be completed due to connection problems with github. I noticed that when I perform a DNS lookup of github.com using google DNS servers i get the "correct/old" ip addresses…
giomanda
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How does a router on the Internet know where to send a packet to next to get it towards its destination IP address?

I've been doing small-time freelance IT work (among other things) for about the last decade now. I've set-up or rebuilt more local network arrangements than I can care to count, and more recently I've been studying up on some of the big gaps that…
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DNS errors after changing nameservers for Cloudflare

I don't know if this is the right place for my question, but I have a problem with my DNS/nameservers after changing the nameservers. I'm not sure if it is a problem at my side or at my webhost. I updated the DNS Zone Records in the Control Panel of…
Jordy
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I have a Cisco Catalyst 2940 and want to connect to it via the network. How to find its IP address?

Since my computer has not serial port, the serial cable is of no help. Does the Catalyst 2940 acquire an address via DHCP? At least my DHCP server doesn't show any address which has been requested recently. Maybe the Catalyst has to be reset first?…
Holger Jakobs
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Is it possible to connect 2 networks with same IP range?

I have two networks with the same IP addresses in use and I need to connect them. I have a third network between the two to connect them but I need to know : - is it possible to communicate iof the IP are the same on both side ? - Which technology…
Stéphane V
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How to obtain incoming ip address from virtualbox

I setup a http server (apache) under VB and forward the port from the host using the available tool in VB. My VB network is NAT connected with the host. However when doing this the access log of http only show the same ip address for every…
iKid
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Static IP Address assignment vs DHCP address assignment

I manage a small-ish network that consists of less than 70 nodes. The previous system administrators opted to have a dhcp server and manually set dhcp addess. I have opted to rather use dhcp address assignment instead of static address assignment…
biosFF
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What is a good default IP address?

My company makes Ethernet devices. These devices have very little I/O. No keyboard, no video output. When the customer gets the device he must configure it for his network. I'd like to choose an IP address that won't conflict with an existing…
Robert Deml
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Finding all Public IPv4 and IPv6 addresses in a UNIX shell script

For monitoring purposes, I'd like to find out all public IPv4 and IPv6 addresses of a mobile-warrior UNIX box. Note that this is different from Finding the Public IP address in a shell script because of the following extra requirements: the mobile…
cnst
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How does 3G/Mobile phones get allocated an IP address? Does this mess with Google Analytics?

This question is in two parts. Q1. How does a mobile phone get an IP address over 3G? Like, would it get the same IP for a shortish period of time (Eg. 1 day, etc)? Because my phone is constantly going in and out of buildings and underground car…
Pure.Krome
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How can I programmatically change a static IP address?

I have a box running windows which I want to assign a static IP to but give remote access to change that IP (without giving complete access to the windows instllation). I want to run a little app or command or something similar to connect to that…
Jon Cage
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Why is this China IP hitting my web site?

I have a web site that uses a couple hundred domain aliases, including franchise-dallas.info, franchise-delaware.info, and detroitfranchise.info (see more below). I have been getting ten to twenty hits per day via Google AdWords PPC. I set up a log…
Evik James
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What could prevent one Amazon EC2 instance from pinging another instance's Private IP?

I have multiple Amazon EC2 instances which need to communicate using private IPs. However, so far I've been unable to ping one instance's private IP from another instance. I can ping external addresses, such as their Elastic IPs and other sites…
ks78
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