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Questions tagged [tcpip]

Transmission Control Protocol (TCP) and Internet Protocol (IP) provide end-to-end connectivity specifying how data should be formatted, addressed, transmitted, routed and received at the destination.

401 questions
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What are CLOSE_WAIT and TIME_WAIT states?

When I do netstat -a on my Windows machine, I get a listing of the ports with one of the four states: - LISTENING - CLOSE_WAIT - TIME_WAIT - ESTABLISHED What do CLOSE_WAIT and TIME_WAIT mean/indicate?
Lazer
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7 answers

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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5 answers

Why are home networks prefixed with 192.168?

Why are home networks prefixed with 192.168 ? Why those numbers? For some historical reasons?
alex
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52
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11 answers

How to find the MAC address of a remote computer?

I know the IP address of a host on my own LAN. Using that, how can I find its MAC address (without having to physically access it)?
Frederick
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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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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 Microsoft say Hey, pick a number 1 to 255....who…
Adam
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42
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8 answers

Why is it bad to have open ports?

Here's something that has always baffled me. Why is it bad to have open ports on your computer? Assuming you don't have a virus on your computer or some other program listening to a port that may actually do something why does it matter if a port is…
aireq
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How do I see which processes have open TCP/IP ports in Mac OS X?

How do I see which processes have open TCP/IP ports in Mac OS X?
yazz.com
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33
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5 answers

How to generate UDP packet

I want to generate UDP packet to test a program, something equivalent to using telnet to test TCP port (Can telnet generate UDP packet?) How can I do this?
Lydon Ch
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28
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5 answers

what is TCP Half Open Connection and TCP half closed connection

I am trying to understand what is the difference between TCP Half Open Connection and TCP Half closed connection can any one tell what exactly are they?
Registered User
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How to kill a particular tcp connection in windows?

On Linux we can kill an Established TCP Connection using tcpkill command. For example, to drop all connection to/from a particular IP: tcpkill host ipaddr Or similary to kill all connection using port 21 at ethernet-1, by: tcpkill -i eth1…
Johnydep
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26
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11 answers

What's the difference between a TCP segment and a TCP packet?

Is a TCP segment not part of a TCP packet? Here's what I've read: A segment is a piece of application data chopped into a transportable size by TCP and wrapped with a TCP header Isn't the TCP header itself made up of segments?
use753231
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24
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1 answer

Is there a hard limit of 65536 open TCP connections per IP address on linux?

Is there a hard limit of 65536 open TCP connections per IP address on linux? I read somewhere that there was, but someone is asking for confirmation and i just can't find it. I seem to remember it was something about the file descriptors being a 16…
Chris
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24
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3 answers

Is your MAC address revealed when you hit up a website?

When you hit up a site, such as cnn.com, does the TCP/IP packet contain the MAC address of your network card? Could cnn.com theoretically record my MAC address?
AngryHacker
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23
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5 answers

How to tell what MTU is being used in Windows XP

I'm suffering from a really weird problem where I randomly get "The connection to the server was reset" errors when trying to access web pages (HTTP error 12031 according to the Windows network diagnostic tool) - this happens regardless of whether…
andygeers
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