Questions tagged [networking]
For questions on connecting devices together so that they can communicate with each other, as well as questions on networking equipment such as routers and switches.
34,791
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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 ...
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507
votes
9
answers
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Did I just get hacked?
I am developing a consumer product, and it is supposed to be connected to the Internet, so as expected, it is connected to the Internet so that I can properly develop it.
I went away for an hour or ...
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487
votes
16
answers
1.2m
views
Test if a port on a remote system is reachable (without telnet)
In the old days, we used telnet to see if a port on a remote host was open: telnet hostname port would attempt to connect to any port on any host and give you access to the raw TCP stream.
These days,...
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390
votes
1
answer
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Ping faster than light
I just discovered very strange thing while testing my internet connection.
My ping is smaller than it should be. For example ping time to Arizona State University is about 14ms.
eryk@eryk-pc:~$ ping ...
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352
votes
19
answers
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How to reliably keep an SSH tunnel open?
I use an SSH tunnel from work to go around various idotic firewalls (it's ok with my boss :)). The problem is, after a while the ssh connection usually hangs, and the tunnel is broken.
If I could at ...
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348
votes
5
answers
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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?
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5
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What does the "Fi" in "Wi-Fi" mean?
I just got into a heated discussion about Wi-Fi. What does the Fi in Wi-Fi mean? I would have thought potentially "frequency interface" since all network adapters are classified as interfaces. However ...
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votes
10
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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++.
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votes
11
answers
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Is it possible to ping an address:port?
I am not into networking, and I have the following question related to the Linux ping command.
Can I only ping an address? For example:
miner@raspberrypi ~ $ ping onofri.org
PING onofri.org (67.222....
- 7,201
253
votes
4
answers
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Connect to the host machine from a VirtualBox guest OS?
I'd essentially like to access my host computer from the guest in VirtualBox. Is there an IP address given for my host which I can use from the guest? Are there extra steps required to set this up? I'...
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226
votes
15
answers
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How do I know what proxy server I'm using?
I need to know what the address for my proxy server is so I can configure another program to also use it. If I go into IE, Internet Properties, LAN Settings, then all I see is an automatic ...
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218
votes
3
answers
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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/...
- 17.8k
213
votes
7
answers
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scp between two remote hosts from my (third) pc
I have two remote hosts.
host1-> 10.3.0.1
host2-> 10.3.0.2
Both run an ssh server.
The ssh server listens on port 22 in host1 and on port 6969 in host2.
Now, using my local machine, I need to copy ...
- 2,231
208
votes
12
answers
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Disable "These files might be harmful to your computer" warning?
I keep getting this irritating warning when copying files over the network:
These files might be harmful to your computer
Your internet security settings suggest that one or more files may be harmful....
- 24.2k
198
votes
13
answers
407k
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How can I make the Windows VPN route selective traffic (by destination network)?
I want to use a Windows VPN but only for a particular network, so that it doesn't take over my entire network connection.
e.g., Instead of the VPN becoming the default route, make it only the route ...
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191
votes
23
answers
423k
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Why is 'ping' unable to resolve a name when 'nslookup' works fine?
On my Windows XP workstation, I can find the machine I want to connect to in DNS with nslookup:
nslookup wolfman
Server: dns.company.com
Address: 192.168.1.38
Name: wolfman.company.com
Address: 192....
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166
votes
2
answers
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What is a "Magic Packet" for waking a computer?
My wireless adapter (Intel Dual Band Wireless-N 7260) has two settings in Device Manager which I cannot explain.
Wake on Magic Packet
Wake on Pattern Match
After a bit of research, I found this ...
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158
votes
9
answers
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How can I scan the local network for connected devices in Mac OS?
I'm basically looking for something like this but available on Mac. I am using Mac OS X 10.6.
I am trying to connect a new workstation to our wireless multifunction printer and I'm having a hell of a ...
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153
votes
2
answers
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Why is X11 forwarding so inefficient?
Whenever I remotely launch large GUIs with X11 forwarding, even including the -C switch, the experience is very unresponsive. My question is, what does, at the concept/protocol level cause this?
With ...
- 1,571
151
votes
5
answers
177k
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How to selectively route network traffic through VPN on Mac OS X Leopard?
I don't want to send all my network traffic down to VPN when I'm connected to my company's network (via VPN) from home. For example, when I'm working from home, I would like to be able to backup all ...
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148
votes
8
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How do I get a static IP address for my teapot?
I maintain this teapot:
It returns a 418 error when it is pinged, and it is pinged regularly by people arriving from the relevant Wikipedia page. (For those interested, and there appear to be a few ...
- 3,470
143
votes
5
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What is the difference between NAT / Bridged / Host-Only networking?
VMWare: What is NAT vs. Bridged vs. Host-Only?
- 1,661
134
votes
14
answers
122k
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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 ...
134
votes
7
answers
108k
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VirtualBox guest OS accessing local server on host OS
On my Ubuntu host I have my local webserver. I installed VirtualBox and Debian as a guest.
I would like the Debian guest to be able to hit my webserver running on my Ubuntu host (for example, I just ...
- 2,371
130
votes
3
answers
169k
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Difference between host name and domain name
What's the difference between Hostname and Domain name? especially in regards to NIC
Could someone please elaborate with examples as this concept is a little confusing
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120
votes
3
answers
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Why does a gigabit/sec Internet connection via cable (coax) not offer symmetrical speeds like fiber?
In our area, we have Cox Communications (cable) which offers 1 Gbit/s down, and 30 Mbit/s up, while CenturyLink (fiber) offers 1 Gbit/s up and down.
Why does copper only 'allow' fast speeds for ...
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119
votes
7
answers
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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 ...
- 6,151
119
votes
10
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Make Windows 7 ignore WiFi when ethernet is available
When I dock my Windows 7 laptop, I want it to prefer the wired ethernet connection over WiFi.
This is a pretty straightforward thing to do on my Mac - I just reorder my network preferences, and it "...
- 1,357
115
votes
6
answers
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Why did the IETF specifically choose 192.168/16 to be a private IP address class?
Why did the Internet Engineering Task Force (IETF) choose 192.168/16 to be a private IP address classand not something else?
Why specifically 192.168/16 and 10/8 and 172.16/12 and not 145.243/16 for ...
- 1,360
114
votes
5
answers
172k
views
How can I find out where an email really came from?
How can I know where an email really originated from? Is there any way to find it out?
I have heard about email headers, but I don't know where can I see email headers, for example in Gmail. Any ...
- 1,562
107
votes
4
answers
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How can I clear the IP address of Ethernet interface without cycling the interface up/down or restarting it
What is the Linux command to clear IP addresses of an interface without bringing it down and/or restarting network services?
Seems strange that ifconfig is able to change IP addresses but has no ...
- 3,030
107
votes
8
answers
356k
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Is there a good tool for monitoring network activity on Mac OS X? [closed]
Is there a good bit of software on Mac OS X that I can use to monitor incoming and outgoing network activity? Nothing too geeky, I just want something simple to use.
I'm on version 10.6 (Snow Leopard)...
- 1,191
105
votes
11
answers
385k
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Display list of computers on a LAN in Linux
I'm a web dev who is trying to get a better handle on security. I'm trying to figure out a way (on Linux/Debian based distros) to list all computers on the same LAN my netbook is on. I tried "arp -n" ...
- 2,395
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votes
12
answers
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Use VPN connection only for selected applications
I have access to a VPN and want to use it only for some applications, not all.
For example:
If I connect to a VPN I want only the applications Opera and Newsbin to use that VPN connection. All other ...
user18861
104
votes
4
answers
209k
views
What's the difference between RDP vs VNC?
What's really the difference between the RDP and VNC?
They both provide the same function and features?
- 2,435
103
votes
9
answers
404k
views
How to do networking between virtual machines in VirtualBox?
I have two virtual machines in VirtualBox. I would like to do networking between them. For the moment I have the default configuration on both, but they seem to have the same IP-address 10.0.2.15. I ...
- 27.8k
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votes
9
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Why is dial up so slow?
On a dial-up Internet connection, why is the speed is limited to 56 kbits/s compared to a broadband Internet connection which may carry 10 times as much as dial up through that same telephone line?
...
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96
votes
6
answers
78k
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Why is localhost IP 127.0.0.1?
I wondered what is the origin of the decision to make localhost's IP address 127.0.0.1. What is the "meaning" of 127? what is the "meaning" of 0.0.1?
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votes
5
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How to get VirtualBox VMs to use host's DNS?
I use VirtualBox for my VMs. My office network setup is wireless, i.e. I connect to my company's WiFi network, which has a local DNS to resolve local names (such as something.mycompany.com going to ...
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votes
10
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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 ...
- 1,053
94
votes
7
answers
181k
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What's the easiest way to sniff TCP traffic data on Linux?
I want a simple way to show all the TCP data (not the TCP headers or anything else) going over any interface on my Linux box.
For instance, I want a magical command that if I do:
...
93
votes
7
answers
13k
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Why do some RJ45 plugs have the lock release clip under a rubber cover?
Some RJ45 plugs have an exposed lock release clip, like this:
However, others place the release clip under a rubber cover, like this:
I find that the rubber cover is almost never anything but a ...
- 30k
92
votes
2
answers
20k
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Why does Qatar use a single IP address when 800,000 IP addresses are allocated to it?
In discussions about IP address banning, IP 82.148.97.69 is often cited as an example. According to Wikipedia, this IP address is the public address of "the entire nation of Qatar". There are two ...
- 9,447
91
votes
2
answers
10k
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How do web-servers "listen" to IP addresses, interrupt or polling?
I'm trying to understand the lower details of web servers.
I am wondering if a server, say Apache, is continuously polling for new requests or If it works by some sort of interrupt system. If it is an ...
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votes
4
answers
542k
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List mapped network drives from the command line to text file
Is there a command that can be used from the command line to output a list of the mapped network drives on the local system and their location on the network to a text file?
This will only be used on ...
user35406
86
votes
3
answers
296k
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How to share any folder without password in Windows 8/10 in a home network if a Microsoft account is involved?
My question is: How to set up file sharing correctly, in a home network, with Windows 8/10, so sharing any folder with "Everyone" (File Explorer->Right click on folder->Properties->Sharing->...
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votes
7
answers
175k
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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 ...
83
votes
9
answers
19k
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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 ...
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83
votes
3
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How can I change the default website connection timeout in Chrome?
I want to change the default timeout in Chrome. In Firefox I can set the value of network.http.connection-timeout in about:config - but how can I do that in Chrome?
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votes
3
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How do you get loopback addresses other than 127.0.0.1 to work on OS X
According to everything I read, the entire 127.x.x.x subnet should loopback.
However, on my Mac, I can only ping 127.0.0.1
I know I've done this before (though possibly on another OS) and has come ...
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