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Questions tagged [ipv4]

Refers to the 4th revision of the Internet Protocol, where addresses are usually displayed in the form: 192.0.2.235

The IP address of a device is its unique identifier on a network which allows communication with that device.

A network will expose a few addresses to the outside Internet and machines on that network will communicate via these gateways.

Due to the explosion of devices connected to the Internet there are real fears of IPv4 address exhaustion which has led to the use of addresses.

IPv4 on Wikipedia

463 questions
367
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5 answers

What's the difference between 127.0.0.1 and 0.0.0.0?

I understand that 127.0.0.1 points to localhost, and so does 0.0.0.0 (correct me if I'm wrong). So, what's the difference between 127.0.0.1 and 0.0.0.0?
Sagnik Sarkar
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Strange dotless decimal notation of IP address... How does it work?

Earlier today I thought I had a URL in my clipboard, but I actually had four 9 digit integers copied from a spreadsheet, which were identification numbers from a proprietary system. Completely unrelated to the task at hand. I pasted it into Firefox…
beeks
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Is there any benefit to using IPv6 on my home network?

I know that IPv6 is the future because there is only 4 billion IPv4 address, but on a home network, you are not going to have 4 billion users. So are there any other benefits that would make IPv6 on a home network better than using IPv4?
Macha
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2 answers

How to force Java to use IPv4 instead IPv6?

My Java browser plug-in is no longer working. When I open a page that has a Java element, Java cannot connect to the server. After investigation, I found that Java was trying to use IPv6, while my network does not support IPv6, so Java always fails…
nyongrand
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52
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8 answers

Why do ISPs change your IP address?

Is there any specific reason an ISP will need to change your IP address? What is the purpose of a dynamic IP versus a static IP? For me it seems to happen every 6 months, while for someone I know, it does once a week.
agz
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49
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7 answers

What does it mean to have a subnet mask /32?

I see in this question, the routing table has: 192.168.1.1/32 link#4 UCS 2 0 en0 openwrt.lan 46:94:fc:63:fc:7 UHLWIir 11 3610 en0 1200 192.168.1.125/32 link#4 UCS …
Number945
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49
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6 answers

Why can't I use the first or last address in a subnet?

I have network with a range 10.0.0.0/24. This means I have 10.0.0.0 to 10.0.0.255, however I cannot use 10.0.0.0 or 10.0.0.255, but I can use anything between that. Why is this? The mask 255.255.255.0 implies that the last digit is the host address,…
John K
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12 answers

Why do I get "General Failure" when pinging host name on a Win 7 node on the network?

This is a very peculiar problem with a station on our network. The client pc is running Windows 7 Pro. What makes this problem interesting is that this client is the only node on the network that seems to be experiencing this proglem. When I try…
Chad Harrison
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36
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5 answers

How can every single device on a network have a different public IP?

I'm at a computer camp, and I noticed that every single device connected to the network has a different public IP, which really surprised me. What is even more strange is that their public IPs are exactly the same as their private IPv4 addresses.…
Flare Cat
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31
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2 answers

Can a domain name have both IP addresses (IPv6 and IPv4)?

Can a domain name (example.com) have both the IP addresses, IPv6 and IPv4? Which IP address does a domain name have? IPv6 or IPv4? But I am not sure that it has both or any one at a time.
Niks
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30
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3 answers

Why can I ping 10.0.0.0/8 addresses from a 192.168.1.0/24 subnet?

My home network uses a 192.168.1.0/24 subnet, and when I ping 192.168.1.137 I get a response saying the host is unavailable (as expected because I don't have any machines using that address) However, when I ping 10.10.10.140 it: gets a response,…
Ryan Oliver Lanham
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24
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4 answers

Why does the “Internet of Things” enforce the need for IPv6 addresses?

If you have multiple devices in one network, the amount of IPv4 addresses will not increase linearly to accomodate the number of devices. There is just one IPv4 address per Network/Router that is connected to the Internet. How does the “Internet of…
codepleb
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24
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3 answers

How do client applications know to use IPv4 or IPv6?

How do servers/computers/users/applications know to request a resource over the Internet with an IPv6 address vs. and IPv4 address?
Bobby S
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22
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4 answers

Is it OK to use mixed DNS servers (e.g., Google as primary and Quad9 as alternate)?

I used to use Google DNS servers, i.e. 8.8.8.8 and 8.8.4.4, but I couldn't access certain websites. Then I decided to use Quad9 DNS as my alternate DNS server: Now those websites are accessible, but I wonder if it's OK to use mixed DNS servers.
Mori
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5 answers

What is the difference between 127.0.0.1 and my assigned IPv4 address?

I read here that: 127.0.0.1 is the IP (IPv4) address of your local computer, synonymous with localhost. When I run the command ipconfig what I actually see is some other IP address. So I’ve pasted my questions…
Dhiwakar Ravikumar
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