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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How does a computer obtain an IP address via DHCP?

How does the computer know which device on the network to query? How does the default gateway factor into this? Pretty much, what is the chain of events that occurs when a computer tries to obtain an IP address using DHCP? The reason I ask is…
Bigbio2002
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How can I display the IP address of an interface?

If I want to display the IP address that is assigned to eth1, how can I do this in Bash?
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Is there an "official" name to the 0.0.0.0 IP address?

As 127.0.0.1 is known as the loopback address, is there a shorter term to refer to 0.0.0.0 other than "the IP address who means all IP address on local machine"?
Willian Mitsuda
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multiple MAC addresses on one physical network interface (linux)

Simple question: How can I setup multiple MAC addresses on one physical network interface (linux)? Why? My ISP is checking ip<->mac on GW and I d like to route traffic through my "linuxbox" and than forward it with different source ip. Without…
grapefruyt
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IPv4 CIDR Ranges for Everything except RFC1918

I'm looking for a list of CIDR blocks for "The Internet", i.e. everything from 0.0.0.0 to 223.255.255.255, excluding RFC1918 address space of 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 (yes, I know there are lots of little nets in there that are…
Jed Daniels
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Windows Server 2008: specifying the default IP address when NIC has multiple addresses

I have a Windows Server which has ~10 IP addresses statically bound. The problem is I don't know how to specify the default IP address. Sometimes when I assign a new address to the NIC, the default IP address changes with the last IP entered in the…
Cédric Boivin
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What is a link-local address?

I could find some information on the Internet but it is hard for me to understand this information because of the use of technical words. Could somebody please help me with that. Did I correctly understand what I read? Firstly, is a link-local…
Roman
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Customer site is out of IP addresses, they want to go from /24 to /12 netmask... Bad idea?

One of my client sites called to ask me to change the subnet masks of the Linux servers I manage there while they re-IP/change the netmask of their network based on a 10.0.0.x scheme. "Can you change the Linux server netmasks from 255.255.255.0 to…
ewwhite
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Why is ARIN (etc.) allocating such large blocks of IPv6 addresses?

The whole issue of IPv4 depletion and waste seems to be finally getting behind us with the (somewhat) increased deployment of IPv6. The sole purpose of IPv6 was to solve the issue of IPv4 address space running out. If that is the case then why are…
jduncanator
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Are people really going to use public IPv6 addresses on their private networks?

I have been reading the Debian System Administrator's Handbook, and I came across this passage in the gateway section: ...Note that NAT is only relevant for IPv4 and its limited address space; in IPv6, the wide availability of addresses greatly…
Questionmark
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How can I do traffic shaping in Linux by IP?

We have a transparent proxy setup. I tried looking for traffic shaping in Linux, and all I could find online was to limit traffic by interface (eth0/eth1...). I need to limit the bandwidth (never exceeding a specific limit) by IP address or IP…
Osama ALASSIRY
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Why does a VLAN have an IP address?

A dumb question for the majority, but I am interested to know "why does a VLAN have an IP address?" Is this address different from the default gateway? Or is this address, same as broadcast address for this VLAN? IP address 192.168.4.100…
RainDoctor
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Why are Class C IP addresses preferred in private networks?

Why are Class C IP addresses preferred over A and B in private networks? My possible answer is "In class C, the number of host IP address available in the network is less than class A or B thus making it easier for DHCP to manage." But I'd like to…
mauris
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In the output of `last`, what does suffix ".d" after an IP address mean?

In order to find out who was logged in recently on my server I am using the command: There were logins from very strange IP addresses e.g.: username@pc:/home/user$ last username pts/16 59.224.XX.178.d Sun Aug 2 12:26 - 12:27 (00:00) (where…
Jimmy88
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How are cellphone IP addresses assigned?

When my cellphone accesses a website via the tower and its GPRS gateway, NAT ensures that the sites receive a public IP. Would all phones using a single tower have the same IP? If yes, then how can the mass of received HTTP data routed to the…
Robin Rodricks
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