An IP address is a unique network-level identifier assigned to a network-enabled device.

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293
votes
4answers
37k views

Why does pinging 192.168.072 (only 2 dots) return a response from 192.168.0.58?

I mistakenly missed the dot off of an IP address and typed in 192.168.072. To my surprise I connected to a machine at 192.168.0.58 If I ping 192.168.072 I get responses from 192.168.0.58. Why is ...
49
votes
7answers
6k views

IP address that is the equivalent of /dev/null

Is there an IP address that would result in any packet sent to be ignored (blackholed)? I know I can always set up a router with an IP address and then just have it ignore all packets sent to it, but ...
40
votes
14answers
16k views

Fastest method to determine my PC's IP address (Windows)

This may seem trivial but I'm looking for the quickest method to determine my PC's IP address within my network. This changes regularly as I connect from one network to the next via DHCP The ...
27
votes
11answers
136k views

How can I make my IP address appear to be from another country?

How do I make it appear that my IP address is coming from one country while I'm located in another? I live in Germany and some websites (like Hulu or Youtube) don't work because my IP isn't in the ...
24
votes
3answers
43k views

Why is Windows' default IP address 169.xx.xx.xx?

My Windows system got an 169.xx.xx.xx IP address the other day, and I fixed the issue, but why did Microsoft chose this address as the default? Why not 1.xx.xx.xx or 255.xx.xx.xx? Did one guy at ...
24
votes
6answers
18k views

Why is there a difference between ping “localhost” and ping “local IP address”?

Using cmd and ping on Windows gave me the following results: Pinging "localhost": Pinging "192.168.0.10" (local IP address): Aren't both situations exactly the same? I mean, I'm pinging ...
20
votes
14answers
14k views

IP Address vs MAC addresses

why do we need ip addresses if mac address is enough to identify the machine???
16
votes
5answers
1k views

How to go to a website on a shared server by its ip address?

I have a few questions, please help: Fist, I can access Google search just by typing http://74.125.224.211, because this is the IP address returned by nslookup. However, I could not do so with the ...
16
votes
1answer
12k views

What is 127.0.0.2 IP address for?

I'm running the example in hiredis, which is using "127.0.0.2" as the redis server IP, and it is running properly. Actually, the redis server is running on the same machine. I know that "127.0.0.1" is ...
15
votes
8answers
62k views

How can I ping a range of IP addresses simultaneously

I have a bunch of machines on an IP address range which I want to ping simultaneously as a quick and dirty way of telling which ones are switched on. What (free) software can I use to do this? I'm ...
12
votes
6answers
20k views

How To Resolve IP Addresses To Domain Names?

I know it is possible to resolve IP addresses to host names but can IPs be resolved to domain names?
12
votes
2answers
2k views

What about IPv4 class E?

IPv4's class E network (240.0.0.0/4) contains 268 million addresses. Despite the advertisements for IPv6, claiming we have ran out of address space, this block ironically still claims to be "Reserved ...
11
votes
4answers
2k views

Is there a way to obtain the true IP address of someone masking their IP? [closed]

There is someone harassing me through emails and I need to know if there is a legal/legitimate way I can obtain their true IP address. They started masking their IP address after I used the email ...
10
votes
2answers
7k views

Mac OS X: Please explain ifconfig output?

When I do ifconfig on my Mac, I get a list of the following interfaces: lo0 gif0 stf0 en0 fw0 en1 vmnet8 vmnet1 I wonder what each interface is. Also, which of these is the IP interface ? I don't ...
10
votes
1answer
9k views

How does a NAT server forward ping ICMP echo reply packets to users?

NAT uses an IP address port number combination to hash the outgoing requests. Since ping requests consist of ICMP echo request packets, they do not have any associated port number. How does a NAT ...
9
votes
7answers
23k views

What regular expression can I use to match an IP address?

With the following grep syntax I want to match all IP address in a file (from a ksh script) grep '[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}' file The problem: It also matches words ...
9
votes
4answers
590 views

How to put two subnets next to each other?

I've been using this calculator http://www.subnet-calculator.com/cidr.php, and I'm trying to figure out how to put two different subnets next to each other. For example, I want to have a /27 subnet ...
8
votes
9answers
2k views

Tracking my home IP from anywhere on the internet?

I have an ISP that serves semi-permanent IPv4 addresses. They can't promise fixed IP addresses, but unexpected changes are quite rare. This begs me to ask however: what would be the easiest/most ...
8
votes
6answers
2k views

What do the different formats for network addresses indicate?

I've seen the following forms for network addresses: 10.1.1.0 172.16.1.0 192.168.1.0 I usually see 192.168.1.0 for my home network address. Sometimes I've seen the other two forms listed above. ...
8
votes
3answers
6k views

What is the maximum number of IPs that can be assigned to a given computer?

I really need to know this for a linux server, but since it also applies to client OSes, I figured the question should be posed here instead of server fault.
8
votes
9answers
12k views

Can ping fine but no browsing

I've got a laptop which has a verified internet connection. I can ping www.google.co.uk and receive a response no problem. However IE, Chrome, Firefox, MSN messenger cannot connect to the internet. ...
8
votes
5answers
5k views

IP address alias assigned by DHCP

I would like to create several aliases to eth0, but have the addresses assigned by DHCP instead of being set to static IP's. Is this even possible? All the examples I've seen assign a static IP using ...
7
votes
3answers
19k views

Whats the meaning of 10.0.0.1/24 address of my computer (ip addr - command)?

Whats the meaning of 10.0.0.1/24 address of my computer (ip addr - command)? 1/24 and not 0/8 10.0.0 range and not 192.168.10
7
votes
2answers
20k views

How to get the real IP address of someone using a proxy?

I was researching digital goods and security when I stumbled upon this company. One of the services they provide is "Real IP". They claim to be able to get the real IP address of users even when ...
7
votes
5answers
847 views

Is it possible to get your router's external ip address without using a website?

I was wondering if there was a way to find out your router's ip address without using a website like www.whatismyip.com. I searched around, and I am beginning to think it is impossible. If that is ...
7
votes
3answers
1k views

Why do the IP addresses randomly change?

I have a network with the following: Cable modem with static IP address Router Desktop - Win 7 VM Host - VMware ESXi 4.0 A couple of VM Guests - Windows Every now and then my Win 7 PC is unable to ...
6
votes
3answers
2k views

How can I make my PC always take the first local IP from the WiFi router?

I share multiple devices on a single WiFi router. They all are assigned local IP addresses (192.168.x.x) depending on a first-connect, first-assigned basis I think. Is there a way to make one device ...
6
votes
5answers
4k views

How to know the IP address of a Mac when it is in network

My Mac mini is connected in a network ( LAN ). As every one knows, each system in a network - has a unique ip address. My Mac mini's IP address is: 192.168.32.164. My Mac is connected to the network ...
6
votes
6answers
24k views

Set up two (2) IP addresses on the same network card?

I think it is possible to set up 2 IP addresses and subnet masks on one NIC in Windows XP. How can this be done?
6
votes
2answers
10k views

How can I specify IP and ports for a hostname in the Windows hosts file?

I want to specify host names with two different ports in the Windows hosts file. Is there a way to do it? Or is it not allowed by Windows itself? I have been wasting my time searching for the ...
6
votes
2answers
909 views

What public IP should I use for long-term network test?

What IP address is OK to ping -f for a prolonged time (the whole day)? "4.2.2.2" or something else? The main concern is the admins there that may decide that it is some DoS and block/complain... ...
6
votes
5answers
10k views

Is it possible to host a web server from behind a NAT

My PC is behind a NAT router that has a public IP address. If I want to host a website then I believe I need a domain name which I can purchase from some site which would pledge to resolve all DNS ...
6
votes
3answers
238 views

Two websites give different values for my IP

I just found something curious: http://whatismyip.org/ says my IP address is 82.44.14.246 http://www.whatismyip.com/ says my IP address is 31.52.118.197 I'm based in the UK and behind a router ...
5
votes
7answers
8k views

Make dynamic IP address fixed?

I am using Time Warner cable internet service. My IP address changes every couple months. However, I need to access some access limited servers which has firewall rules on it. Is there any way to ...
5
votes
3answers
824 views

What happens when all IP addresses run out?

I recently read an article in which they wrote that that there will be a time when there will be no more IP addresses available. Is that right? Do I need to register a website now just in case?
5
votes
4answers
546 views

Duplicate IP Adresses

My roommate and I are experiencing a problem in that our computers have the same IP address. I have a laptop and he's got a desktop, and only recently did this occur, in the past day or two. Is there ...
5
votes
4answers
10k views

Getting the local IP address in Ubuntu 10.04 LTS

I am trying to get my locally assigned IP address from Ubuntu 10.04 LTS with ifconfig and what I'm getting is my external IP address (in other words, it's the same IP I see on whatismyip.com) When ...
5
votes
7answers
21k views

Show all machine's internal IP addresses (Windows XP)?

I have 3 Windows XP machines connection in a small home network. (2 of the 3 have no screen or keyboard.) What's the easiest way for me to find out each of the machines internal IP addresses? Is ...
5
votes
3answers
3k views

How discover duplicate IP using Ubuntu? (is it possible to have duplicate ip?)

I have a problem in network sharing using SMB protocol. I think it's related to IP-duplicating issue. How to detect this. Note: I'm using Ubuntu on my desktop the other are using various OSs (win xp, ...
4
votes
7answers
722 views

Getting my IP address?

My system has a dynamic shared IP provided to me by my ISP. I want to give my IP address to a friend so she can allow access to her server for requests coming from my IP. Can someone please tell me ...
4
votes
5answers
272 views

Home IP Address Management?

Are there any better, free solutions to managing static IPs at home than a spreadsheet?
4
votes
2answers
1k views

I'm Looking For A Good Resource For Learning DNS, IP, and Network Addressing

Any recommendations on books, websites, or other resources for learning Internet Protocol, the ins and outs of DNS and how Networking and IP Addressing works? I have a fundamental knowledge of this ...
4
votes
1answer
340 views

Why does MacOSX try to resolve zero padded IP addresses as host names?

This one caused a friend some headache when setting up a switched internet connection which had zero padded IP addresses in the configuration paper like so: 192.168.019.254 No matter how he tried to ...
4
votes
3answers
14k views

How to block incoming connections from one IP address?

I have found out that one IP address is trying to RDP to a machine. I would now like to get XP to block all incoming connections from this IP address, and I am finding it very frustrating how ...
4
votes
6answers
1k views

user friendly name for ip address on home network

How can I set up some sort of local DNS service, so that instead of using ipaddresses to do things like VNC and remote desktop a more URL like thing can be used. All the devices on a network have a ...
4
votes
9answers
17k views

Getting IP Address of Access Point

recently I turned my Router to a wireless access point for my home network. Unfortunately, I forgot to note down the AP's IP Address and Subnet. How do I reliably get the IP of my AP? Thank's in ...
4
votes
3answers
11k views

Is it possible to get the NAT Ip Address?

is it possible to get my nat ip address across the Internet? I know I can see my ISP address but not my internal address. I remember seeing this done one time but I am thinking it was a java applet ...
4
votes
2answers
927 views

Why does computer connected via wireless and wired have different address but same name?

I have a Thomson TG585 v7 router that can be access via a webbrowser on ipaddress http://192.168.1.254/ I have various computers connected to it via wireless or ethernet in some cases both and I've ...
4
votes
1answer
1k views

IP address spoofing using Source Routing

With IP options we can specify the route we want an IP packet to take while connecting to a server. If we know that a particular server provides some extra functionality based on the IP address can we ...
4
votes
1answer
1k views

How to really change programmatically ip address without reboot (with no connection too)?

Really, I tried everything, and there is no solution that works for me. WMI - everything perfect, but I can't change ip address when there is no connection. O_o Are you joking me? How can I make a ...