Questions tagged [ip]

The IP (internet protocol) is a protocol for transmitting data over packets ("datagrams"). It is the primary protocol of the Internet. "IP" may also refer to an IP address, the numerical address assigned to an IP-capable device.

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17
votes
1answer
14k views

Network devices getting an IP address in the 169.254.x.x range?

I'm totally confused by what's happening to my wifi router, so seeking help here. Configuration I have a modem/wifi router (Netgear CG3000D—let's call it main) connected to cable and configured with ...
381
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4answers
53k 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 ...
74
votes
15answers
279k views

Windows command that returns external IP

Is there a command by which I can find my external IP of my router or my NAT\DSL Router, etc., eliminating the need to visit whatsmyip.net or similar.
24
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9answers
54k 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 ...
15
votes
2answers
17k views

How does the router know which device to send packets to? [duplicate]

my question does not concern how it moves through the internet, but how it moves through the router to a certain device. All devices connected to a router in a home network have the same external IP. ...
127
votes
13answers
110k views

What is the exact use of a MAC address?

I understand that IP addresses are hierarchical, so that routers throughout the internet know which direction to forward a packet. With MAC addresses, there is no hierarchy, and thus packet forwarding ...
25
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2answers
68k views

How do I setup a virtualbox server with a static ip?

I'm trying to get a Virtualbox instance running with a very specific networking setup. Here's what I have right now: I have a laptop running Ubuntu, hosting a Debian Virtualbox. My loptop regularly ...
83
votes
9answers
19k views

Can you grab any IP address on the Internet?

On a personal network (LAN) one can simply grab an IP address. If you choose the same IP address as an existing client, you get problems. There are companies like IANA and ICANN that are in charge of ...
92
votes
10answers
31k views

Are IP addresses with and without leading zeroes the same?

I have a security system and the network setting only allows a three-digit IP address. I can't set it to 192.168.2.100, instead I have to use 192.168.002.100. Are these two IP addresses different? Do ...
16
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2answers
6k views

How do DNS servers work?

I know that a domain name is resolved by a DNS server to an IP address, which is then used to reach the requested server. I'm slightly embarrassed that I don't know some of the details of how this ...
9
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3answers
51k views

How to get assigned IPs by hostednetwork?

I just started using Microsoft Virtual WiFi or hostednetwork from Command Prompt to share my internet connection through my WiFi adapter and it's good so far! The only issue I face however is that I ...
20
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6answers
20k views

Add a static IP alias to a DHCP interface on Windows 8 (and above)

I have a Windows 8 machine that has only a single Ethernet port. It needs to use DHCP and also needs a static IP. Each IP is in a different subnet, and each serves a different, incompatible purpose. ...
20
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4answers
70k views

How do I find out which program and process ID accesses a given IP address in Windows?

Is it possible to catch, which program is accessing a specific IP address? I found my computer is flooding and wish to check addresses one by one. May be it is possible to set up some audit for ...
21
votes
3answers
53k views

How to map an IP adress to localhost?

I want to map the IP address 192.168.1.222 to 127.0.0.1 so that if I use 192.168.1.222 in the web browser or ping command I get the response (and that from my 127.0.0.1). Is this possible via ...
4
votes
1answer
9k views

Accessing a website via the webservers public IP from a PC within the same LAN

If two machines reside on the same LAN (a PC and a Webserver) why is it necessary to enable ‘NAT loopback’ on the router in order for the PC to access the website hosted on the webserver using the ...
6
votes
2answers
28k views

Is 225.225.225.128 a valid subnet mask?

I have been told that we have two devices on a network: 10.40.225.142 and 10.40.225.144 These devices both have Gateway 10.40.225.129 Subnet mask 225.225.225.128 (note 225 is Not a typo) These ...
8
votes
1answer
5k views

* * * in traceroute

If I traceroute to my server via a bunch of different methods, the external ip seems to not work. However the server is online and accessible by this ip. Localhost: michaelxu@michaelxu-server:~$ ...
1
vote
1answer
3k views

TCP/UDP ports that cannot be bound (permission error), but don't show up in netstat

When attempting to listen on certain TCP or UDP ports, I get weird error messages regarding permissions (or generic messages, depending on the program used to bind). The message in German is "Der ...
838
votes
3answers
164k views

Transatlantic ping faster than sending a pixel to the screen?

John Carmack tweeted, I can send an IP packet to Europe faster than I can send a pixel to the screen. How f’d up is that? And if this weren’t John Carmack, I’d file it under “the interwebs being ...
53
votes
7answers
110k views

How can I own an IP address?

How can I own an IP address like I do with domains? I have done some research and it seems that you can't buy a single IP, but rather you have to purchase a range of IP addresses. Update : Important ...
36
votes
9answers
188k views

Find an unknown static IP + subnet mask of device?

I have a device set with a static IP and subnet mask. I do not know the IP or subnet mask. How can I find the devices IP and subnet mask? It is a piece of hardware, not a PC. It will not take an IP ...
32
votes
3answers
9k views

Why does the registered domain name “localtest.me” resolve to 127.0.0.1?

I was reading an article about Server-Side Request Forgery. In that article the attacker found that 127.0.0.1 was open to the internet. The victim then blocked 127.0.0.1, but because many other IPs ...
14
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8answers
100k views

How to get my external IP address (over NAT) from the Windows command-line? [duplicate]

The Windows "ipconfig" command can only show me the parameters from the Ethernet interfaces from my machine (even with the ipconfig /all argument). It can show detailed information about the interface,...
15
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4answers
2k views

Is my router's IP address really public?

I have a common home network consisting of a wireless router with many devices connected to it. I understand that because of NAT, all devices attached to the router connect to the outside of it via ...
6
votes
3answers
24k views

How can I map a domain name to an IP address and port?

I want to give a domain name to the IP address and port for an application in Windows 7. For example, test.com should map to 127.0.0.1:59873. Is there anyway that we can do it by using a web server ...
5
votes
8answers
46k views

How to get LAN ip to a variable in a Windows batch file

I'm streaming audio from my Windows 7 laptop to a sound card attached to a router. I have a little batch script to start streaming. REM Kill any instances of vlc taskkill /im vlc.exe "c:\Program ...
3
votes
1answer
3k views

Using Remote Desktop to connect to different computers behind same IP

I'm trying to connect my computer from home to two computers in my office. The office has a router and I already forward the port for computer A. I can successfully connect to my computer A at my home ...
9
votes
3answers
43k views

Find all past desktop IP addresses

Is there a way to find some type of log file that saves all IP address that were assigned to a desktop? I changed an static IP of a desktop (switched it to DHCP) of mine and i can not recall what the ...
8
votes
3answers
28k views

Why can't IP addresses start with 0 or 255?

It was specified somewhere (presumably in an RFC) that Class A addresses range from 1-126 in the first octet, and that class E addresses range from 240-254, but that leaves out two potential networks ...
5
votes
6answers
48k views

How can I copy a print file to a networked printer?

I have an Epson TM-T88V network printer. I can print to it using the printer driver. But I need to copy a "print file" to the printer using the command line, and this causes problems. I ...
5
votes
1answer
16k views

What information can my ISP see from my router?

I installed a new router today and saw my IP address change because the new router has a different MAC address and I am just curious on what information my ISP can see from my network. I know they ...
6
votes
3answers
1k views

Is it possible that a lower level network can provide IP addresses for the higher level network? And how to prevent that?

Sorry for my obscure title, I don't have much knowledge about networking. So today I got a really strange problem with my network, it's like this: My network: From Internet → my Wi-Fi router → "black ...
2
votes
1answer
3k views

IP-to-IP Redirect

How can i redirect an IP to another IP, cause currently i have a program connecting to old IP address, sadly its hardcoded into it and its impossible to change it without violating its EULA, i want to ...
1
vote
2answers
6k views

how can i forward requests to my own IP address to a local IP address in my network (possibly using named)?

My setup I have a linux server running in my basement. I currently have my router looking to that server for DNS lookup, so I can use named to spoof a bunch of domain names to point to my local ...
248
votes
9answers
615k views

How can I list all IPs in the connected network, through Terminal preferably?

Using Ubuntu 10.10 command line, how can I list all IPs connected to my home network? Ideally, it needs to be a CLI command as I will be running it from C++.
39
votes
12answers
742k views

Windows command to display all IP addresses

I know there is a single line of a command and its arguments that can help display all computer IP addresses (those that are being used) on a LAN, and my computer is also a client, as one of those ...
41
votes
9answers
62k views

Why do we need subnet mask?

Since a IPv4 address already gives the information of the network and and host, why do we still need a subnet mask? The 1st Octet already specify the network class (1-127: A, 128-191: B, 192-223: C ...
29
votes
5answers
38k views

How do IP answer packets reach their destination inside of a private LAN? [duplicate]

This is a little theory question that has been confusing me for a pretty long time. Basically, if we are inside of a private LAN, and we want incoming packets to reach, for example, an HTTP server ...
120
votes
7answers
6k views

Why can't I email myself at: MyEmail@74.125.235.55?

I opened cmd and typed ping gmail.com. It shows me: C:\Windows\system32>ping gmail.com Pinging gmail.com [74.125.235.55] with 32 bytes of data: Reply from 74.125.235.55: bytes=32 time=6ms TTL=56 ...
49
votes
7answers
127k views

Is it possible for many domain names to share one IP address?

Is it possible for many domain names to share one IP address? For example, www.xjtl.com, www.fmie.com, sdmfl.com, etc. Hundreds of domain names share just one IP – when you do a DNS query for each of ...
35
votes
2answers
66k views

How does bridged networking work in Virtualbox?

How does bridged networking work? I have looked through the VirtualBox manuals but nothing extremely technical came up (It was just a generic gloss over of the topic). How does it assign a ...
22
votes
7answers
24k views

Why can a network address not be a valid host address?

So... I have studied for CCNA and such and been working with IP networking at the least the past 8 years or so. I have always seen and been told that the network address for a subnet is not a valid ...
16
votes
3answers
28k views

Wrong IP address from DHCP client on Ubuntu 18.04

I'm experiencing a weird issue where my Ubuntu 18.04 (server) box gets issued a wrong IP address during boot from the DHCP server. Running dhclient after boot on the interface results in the right IP ...
14
votes
2answers
79k 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
13k views

Where are addresses from the network 0.0.0.0/8 used in practice?

I read that this pool: Means "these hosts" in "this network" Is used for self-identification Is used for broadcast messages My questions are: Where exactly these addresses can be found? Which ...
7
votes
7answers
32k views

How do you get your public IP address through the Windows command line?

Is it possible to get your public IP address through cmd without using sites such as http://whatismyipaddress.com/? I am behind a router. Please feel free to go as detailed as possible. I'm studying ...
14
votes
7answers
9k views

Identify an unknown IP in our network

I have a network containing 20 clients. I assigned IP range 10.0.0.1 to 10.0.0.20 to them. When I do an IP scanning I see someone using 10.0.0.131 in VMware. How can I find out which IP is this IP ...
13
votes
5answers
66k views

DHCP Reservation vs Static IP address

So after browsing some websites, some people are telling me that static IP address is the best. But others say the DHCP Reservation is just as good if not the same. So what is better? Or are they ...
6
votes
2answers
22k views

Problem with persistent routes and VPN connection in Windows 7

My home PC has a VPN connection to my office. The office network is firewalled, with a secure zone on 192.168.0.* and a DMZ on 10.0.0.* From outside, www.mycompany.com routes to a public IP - say 1....
12
votes
1answer
2k views

Which IP address do I use to access my server?

I'm running a Samba server on my MacBook and I've also set up port forwarding to said server from my router. My public IP is 106.51.x.x (according to google and a few other services) and my Mac's ...

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