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

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81
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1answer
5k views

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 ...
37
votes
8answers
6k views

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 ...
31
votes
7answers
33k views

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 ...
13
votes
8answers
75k views

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 ...
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 ...
10
votes
2answers
6k views

How can I setup an IPv6 network in this way?

I have a network mapped like this : To experiment with IPv6 connectivity, I want to configure my LAN network using IPv6. Can someone explain how to convert the connection between the Desktop and ...
9
votes
4answers
665 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 ...
9
votes
5answers
2k views

Does NAT provide security?

I'm following discussions about the IPv4->IPv6 transition, and IPv6 doesn't seem to like NAT at all. I've always thought that NAT was helpful in v4 for some security, I know it doesn't really hide ...
9
votes
1answer
19k views

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 ...
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 ...
7
votes
4answers
2k views

Does disabling IPv6 decrease my surface area of attack and increase performance?

I have colleague that is on this whole kick of disabling IPv6 while leaving IPv4 on each new machine that comes in before deploying in our environment. He takes his personal anecdotal evidence and ...
7
votes
1answer
2k views

Is there any reason to subnet a home network?

For networks I understand we set a netmask on each computer to let it know what IPs it can talk to without going through the router - IPs on the same subnet can talk directly to each other and do not ...
7
votes
2answers
5k views

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?
6
votes
3answers
1k views

4in6 tunneling (via OpenVPN?)

I have a local network with internet access. But unfortunately IPv4 internet connection speed is limited to 1mbps, which is realy sad. Fortunately I have a native IPv6, and there is no connection ...
5
votes
3answers
834 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
1answer
537 views

Exactly how many valid IPv4 addresses are there?

Seemingly simple question, with enough edge and corner cases that I don't trust my ability to calculate it. What is the exact number of valid IPv4 addresses that could potentially be used as ...
5
votes
1answer
3k views

IPv6 Tunnel via Own Linux (IPv6-connected) Server

Unfortunately, there's a lot of IPv6 tunnel brokers, and their documentation often clutters the search results for how to setup your own IPv6 tunnel. I have a Linux server with IPv6 connectivity. I ...
5
votes
4answers
3k views

Is it possible to use IPv6 in LAN with router only supporting IPv4?

My router (Belkin N1 Vision) seem to only support IPv4. The problem is that i'm trying to get Windows 7 Homegroup going and it requires IPv6. I'm trying to connect home computer which is connected to ...
5
votes
1answer
1k views

IPv4, IPv6 and IPTables

I have just recently learned that even if I block all traffic to my webserver using iptables it is still vulnerable to external attacks via IPv6. In my understanding, this renders iptables-only ...
5
votes
1answer
211 views

Is there a way to test alternate IPv4 routes?

i am using Hurricane Electric's Tunnel Broker service to get IPv6 connectivity. TunnelBroker lets you have access to the IPv6 Internet by using a standard IPv6 tunneling protocol. You send IPv6 ...
4
votes
3answers
843 views

How to get started with TCP/IP v6?

Now and then there is "news" about that the IP numbers will run out in X years, and we must change to TCP/IP v6... And even though this crisis never really happens it has waken a question, how do ...
4
votes
2answers
6k views

Possible to Use IPv4 and IPv6 at the same time?

Can IPv6 and IPv4 work simultaneously?
4
votes
1answer
212 views

Why does writing IP addresses this alternate way work, and is there a practical use case for it? [duplicate]

Recently I saw an incorrectly typed telnet command, and I saw that "regular" numbers were interpreted to IP addresses. I tried this myself in Windows and the same behavior is shown there, so obviously ...
4
votes
3answers
123 views

IPV4 address changes so it's hard to host a server. How do I change this?

I have a laptop and I am hosting a game server at the moment at home. Now, my problem is while port forwarding I have to add in my IPv4 address while port forwarding. My laptop is connected with WiFi ...
4
votes
1answer
158 views

Get IPv6 address of an IPv4 machine?

Given two machines on a local network, both connected via IPv4 and IPv6, can machine A get the IPv6 of machine B if it has machine B's IPv4 address? I presume the ARP cache should be able to provide ...
4
votes
1answer
209 views

How to block a program from using IPv4?

I have a program that can communicate over IPv4 (TCP and UDP) and over IPv6 (TCP and UDP). I want to block the program from being able to use IPv4. I tried the Windows Firewall: Except it blocks ...
4
votes
1answer
58 views

VirtualBox not allowing me to modify IPv4 Network Mask?

I use Oracle VM VirtualBox to run a web server on my machine. I had it set up and working perfectly for a while. For the past few months it's been prompting me to update, and I finally gave in and ran ...
3
votes
4answers
3k views

How do I properly access Google through IPV6?

I'm trying to access Google through IPv6. However, it seems to want to send me back to IPv4! I did a DNS lookup on IPv6.google.com at http://centralops.net/co/ and found their IP, then tried this... ...
3
votes
2answers
116 views

How does the separation between IP addresses on the internet and on the LAN work?

Complete newbie question: Say for example the address: 8.8.8.8 How does the computer know that this address is on the internet, not the local network? Could a device on the local network have the ...
3
votes
2answers
39k views

Install Internet Protocol Version 4 (TCP/IPv4) on Windows 7

I can not explain what has happened, just suddenly I lost my internet connection. On local area connection properties IPv4 is not installed, my ISP says that they only support IPv4. Then I must had it ...
3
votes
2answers
380 views

Why can I ping 127.1?

I know IPv6 allows consecutive zeros to be omitted. But how about IPv4? I haven't found any reference to this on the Internet, including Wikipedia and RFC 791 – Internet Protocol. This document ...
3
votes
2answers
139 views

Why is tracert showing a private IP address right after my router, even though it has a public IP?

Here is a log of tracert superuser.com from my computer: Tracing route to superuser.com [198.252.206.16] over a maximum of 30 hops: 1 2 ms 2 ms 2 ms 192.168.1.1 2 11 ms 17 ...
3
votes
2answers
64 views

Is it normal for a hosting service to require that I buy a public IPv4 for using my own $25 certificate?

Self explanatory title, I guess. I'd love to have my website in https only, but they (the web hosting service) claim in the administration that I need to buy a public IPv4 address from them before ...
3
votes
1answer
214 views

From where does IP geographical location data come?

I don't understand how some sites (e.g. https://www.ultratools.com/tools/geoIpResult) show country and town for an IP address. For example 193.45.10.135: Continent: Europe Country: Germany Country ...
3
votes
2answers
2k views

Should I get a router with ipv6 support?

I'm in the process of getting a new gigabit router so I can transfer files faster to and from my Lacie Network Space. I found Asus RT-N56U Wireless N Dual Band Gigabit Router. Its performance is ...
3
votes
1answer
1k views

Change permission to /proc/net/ip_conntrack on Ubuntu server 9.10

I have a script that needs to extract certain information form the /proc/net/ip_conntrack file once in a while. I do not wish to run this script as the root user. Default permissions for the file ...
3
votes
1answer
263 views

Can I prioritize IPv6 traffic over IPv4 traffic on Linux?

Is there a way I can give traffic over IPv6 a higher priority than traffic over IPv4? Purpose is 2-fold: Promote IPv6, and be able to connect even when my server is swamped by IPv4 users.
2
votes
4answers
339 views

How common is fancy IP math accepted by tools?

If we specify an IPv4 address we all usually do the pattern of 1.2.3.4 Now essentially this is only 'a' way of writing a 32 bit number in a more human readable form. The IP address 1.2.3.4 can also ...
2
votes
2answers
568 views

How does CIDR slow the exhaustion of IPv4?

In the Wikipedia article on CIDR, it says The Internet Engineering Task Force introduced CIDR in 1993 to replace the previous addressing architecture of classful network design in the ...
2
votes
2answers
424 views

Doubt In default time to live (TTL) 255?

I know that,The Default Time to live value is 255, each time a ipv4 packet crosses a router that value is decremented by 1. But,When I ping my adsl router it shows TTL as 64 Pinging 192.168.0.1 ...
2
votes
3answers
709 views

Why were the ipv4 private address ranges chosen to be what they are? [duplicate]

Possible Duplicate: Why are home networks prefixed with 192.168? What makes the numbers 192.168 or 10. or 172.16 so special that those addresses, as opposed to other ones, were chosen as ...
2
votes
2answers
124 views

Is it possible to change my IPv4 address?

At home, when I type in ipconfig in the command line, I would find that my IPv4 address is 192.168.8.x. However, at office, when I type in ipconfig in the command line, the IPv4 address is ...
2
votes
2answers
419 views

Unable to ping broadcast address

Host address: 192.168.0.13 Network: 192.168.0.0 255.255.255.0 Router: Cisco DPC3825 DOCSIS 3.0 Gateway (user manual) My home network uses the 192.168.0.0 /24 network for my (mostly wireless) ...
2
votes
2answers
83 views

Wireless Internet is “Unidentified”?

My laptop wireless refuses to connect with my wireless adapter. It says signals all good and ip address is cool, but my ipv4 ad ipv6 connectivity is "no netwok access". What do i do with that?
2
votes
1answer
120 views

static IP outside of subnet range

I have two questions, but let me explain the situation first. They are about the (static) IP address of a printer attached to the network. We had this networking setup, using a normal consumer router ...
2
votes
3answers
2k views

SSH tunnel in Ubuntu

How do I create a ssh tunnel in Ubuntu that is persistent? I have tried a lot of ways but I haven't gotten it to work.
2
votes
1answer
384 views

Windows IP conflict after setting Static IP

I am having troubles setting my static IP address. I double check all of my default settings and tried to make my IP static. Here is what I entered I have tried various different IP addres ...
2
votes
1answer
446 views

Using router public IP to access another (located in WAN) router behind NAT

I have following setup: at home I have a router up and running with public ipv4 ip at my country house I have ipv4 cam and router which is behind NAT - no public ip (public ip is too expensive) both ...
2
votes
1answer
103 views

IPv6 only LAN with NAT64 router for Internet

I want to disable IPv4 on my LAN and run only IPv6. I will use a NAT64 Juniper firewall to provide Internet access since I only have IPv4 Internet. Will this break applications? Will I be able to ...
2
votes
4answers
6k views

Ping myself, works with ipv6 not ipv4 in Windows 7

I've tried to solve the following problem with no luck and I need some proffesional help. The following is possible: Ping all computers (that I tried) in the domain without problem. Ping myself ...