Networking is the art of connecting two or more devices together so that they can communicate with each other.
561
votes
3answers
115k 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 ...
85
votes
9answers
6k views
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?
...
49
votes
8answers
34k views
What is the difference between various cable types like Cat 5, Cat 5e and Cat 6?
I'm just about to move house, so I'm going to have to disconnect and re-wire my network. Pretty much all the devices I have support Gigabit Ethernet. Should I go out and buy some decent network cables ...
47
votes
5answers
14k views
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?
47
votes
9answers
212k views
How to install Windows 7 from the network?
Is it possible to install Windows 7 (Current RTM Version) on a computer without using removable media like DVD or USB?
The first thing that comes to my mind is through the network, but I don't have ...
46
votes
8answers
22k views
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 ...
35
votes
6answers
29k views
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 ...
34
votes
3answers
2k views
What's 24 in “192.168.15.0/24”?
What's the meaning of /24 in the following command?
route add -net 192.168.15.0/24 192.168.8.10
33
votes
4answers
56k views
How can I list all IPs in the connected network, through Terminal preferably?
Using Ubuntu 10.10, I was wondering if there was a command line command that can list all the IPs of devices connected to the network?
I would use this for example, to list all the computers ...
33
votes
4answers
34k views
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 my ...
29
votes
10answers
29k views
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 ...
29
votes
3answers
2k views
Can admins monitor my activity locally even when I use a VPN?
My school has one of those super overreacting web blockers (specifically Fortisnet) that blocks things that should be accessible by a high-school senior trying to research projects. Despite many ...
28
votes
7answers
22k views
How to throttle bandwidth on a Linux network interface?
Is there a way to constrain the bandwidth on a NIC in linux? I'd like to be able to simulate an arbitrarily slow connection.
27
votes
10answers
19k views
Can I make two wireless routers communicate using the wireless?
I want to make a setup like this:
cable modem <-cable-> wireless router 1 <-wireless-> wireless router 2 in another room <-cables-> PCs in another room
Basically, I want to extend my ...
26
votes
9answers
47k views
Is there a good tool for monitoring network activity on Mac OS X?
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 ...
25
votes
5answers
2k views
How do I tell Windows to use 802.11 in preference to 3G?
I have a Samsung NC-10 netbook which I take to work every day. Most of the time I use it just on the train/bus, but I also use it at work and home.
It has a built-in 3G card which I want to use when ...
24
votes
5answers
1k views
What gets uploaded when I surf the web?
I am using a modem, and it shows a download speed of n kbps and an upload speed of m kbps. When I check its logs, it shows the amount of data downloaded and uploaded. I'm wondering why it shows that ...
24
votes
7answers
47k 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 ...
23
votes
6answers
28k views
What is a subnet mask, and the difference between a subnet mask of 255.255.255.0 and 255.0.0.0?
My DSL/WiFi router provided by my ISP has an internal IP address of 10.0.0.138, the addresses provided by DHCP are in the format of 10.0.0.xxx.
Now, I want to start using static IP addresses on my ...
20
votes
14answers
9k views
IP Address vs MAC addresses
why do we need ip addresses if mac address is enough to identify the machine???
19
votes
8answers
4k views
How to track LAN usage? (AKA 'top for LAN')
There's an evil application that is eating ALL my upload bandwidth (I'm brazilian, it's only ~35kbps) for like 80% of the time my PC is turned on.
I would like to know if there's any way to track ...
19
votes
4answers
12k views
Is there a way to find out what application using most of bandwidth in Linux?
I'm looking for an utility that could show me how much of a bandwidth each process are using. It should just print the data and exit as I want to feed that list into conky.
19
votes
4answers
27k views
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 ...
19
votes
3answers
4k views
Are MAC addresses unique when coming out of the factory?
According to Wikipedia:
A Media Access Control address (MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segment
But how unique are ...
18
votes
4answers
16k views
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? ...
18
votes
3answers
38k views
List Mapped Network Drives from 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 txt file? This will only be used on ...
17
votes
4answers
6k views
What is VPN actually used for?
I've never really understood why VPNs are used. I know it stands for Virtual Private Network, but in simple terms how does it work and what is it used for?
17
votes
8answers
8k views
How can I join two simple home networks together using an ethernet cable?
I want to join two different home networks together like so:
PC A1 PC A2 PC B1 PC B2
\ / \ /
Gateway A ...
17
votes
3answers
9k views
Which home router support IPv6?
Which routers suitable for small/home networks support IPv6 as described in the Microsoft document IPv6 Support in Home Routers?
Edit: to answer some comments wondering about the reasons of wanting ...
16
votes
8answers
2k views
What are the disadvantages (if any) of accessing the internet through two or more “chained” routers?
My Problem
I just got internet setup in my dorm room at school through a third-party provider. The modem they gave me, however, also functions as a wireless router. I also have my own router with ...
16
votes
6answers
61k views
How do you automatically detect a new network card in CentOS 6 / RedHat?
I'm using CentOS 6 in a virtual environment. When cloning a virtual version of CentOS, the old eth adapters are "removed" and replaced with new ones and net MAC addresses. However, the ifcfg-ethn ...
16
votes
2answers
629 views
What is a hostname?
I'm setting up a Fedora 15 box in my local network. It's going to have Internet access and share media stuff like photos.
In one step of the installation process it asks for "hostname", what could ...
16
votes
2answers
6k views
How to start networking on a wired interface before logon in Ubuntu Desktop Edition
Problem
Ubuntu 9.10 Desktop Edition (and possibly previous versions as well, I haven't tested them) has no network connections after boot until at least 1 user logs in. This means any services that ...
15
votes
7answers
14k views
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:
...
15
votes
6answers
1k views
Will the ethernet pull bandwidth if unplugged?
I'm fairly certain that this isn't a problem, but like a phone charger it will still pull electricity even though you aren't charging anything if you leave it plugged into the wall. Though minimal it ...
15
votes
7answers
524 views
Common mistakes on home wireless network
Besides not setting a password, what are other common mistakes made when setting up a wireless network?
15
votes
6answers
1k views
Can a huge coiled LAN cable have some trouble for transmitting a signal?
Let's say I have a long (> 30m) LAN cable, that connect two (very close) devices.
Could some of the unused wire, disposed as a huge coil, cause any issue ? I'm thinking about the special wire layout ...
15
votes
13answers
7k views
Visual Network Topology Map?
If I have no idea of the current network setup, and I'm connected to the LAN - is there any GUI that could possibly identify nodes visually or give me any sort of insight?
I'm looking for a more ...
15
votes
12answers
56k views
Windows 7 intermittently drops wired Internet/LAN connection
In a nutshell, my Windows 7 Ultimate PC intermittently drops its Internet connection. Why?
Background: My PC is wired to my ADSL modem/router which is directly connected to the phone line. I also ...
15
votes
4answers
7k views
How to use different network interfaces for different processes?
I have two network interfaces on a Linux PC, and I need to manually set the interface that a given process will use.
The program (Twinkle softphone) does not have a similar option, so I believe that ...
15
votes
1answer
8k views
Mac Wireshark alternatives [closed]
Do you know any good alternatives for wireshark (network analyzer) running on a Mac OS X 10.5+?
Wireshark is not that handy like on an Windows OS (user interface with X11, ...).
Any kind of help is ...
15
votes
6answers
35k views
Share single iTunes library across multiple computers
I have a large (> 2TB) iTunes library of music and videos that I keep on a Drobo connected to an Airport Extreme base station so that I can access it wirelessly from my MacBook. This works great for ...
14
votes
4answers
3k views
Ethernet vs TCP vs IP?
What is the difference between Ethernet, TCP, and IP in simple (simple abstract) terms?
Please do not copy from Wikipedia...
14
votes
8answers
32k views
How can I ping a range of IP addresses simultaneously
I have a bunch of machines on an IP address range which I want to ping simultaneously as a quick and dirty way of telling which ones are switched on. What (free) software can I use to do this?
I'm ...
14
votes
5answers
2k views
How do I pre-wire my home right?
This seems like a good place to ask this. I'm sure many of you have done this in the past.
I am getting a home built and will soon be making decisions on all the pre-wiring.
I know I want to run ...
14
votes
4answers
2k views
Are Domain Name Server and Name Server the same thing?
I am slightly confused between DNS and Name server. Are they the same thing or is there a difference between two?
14
votes
4answers
26k views
When concurrently connected to wired and wireless ensure Windows 7 uses wired connection
When I am at my desk and my laptop is in its docking station I want to ensure that it uses its wired connection and not my wireless network. I am hoping/guessing that the preference in connection is ...
14
votes
2answers
917 views
Does https encrypt URLs, too?
This is fairly easy.
If I go to https://webserver.com/someurl?a=b, will the someurl?a=b part be protected, or just the contents of the site?
14
votes
3answers
49k views
Permanently map a network drive on Mac OS X Leopard
I want to have a mapped drive in Mac OS X which points to my NAS - however I've found that I have to do it after every single reboot.
I'm a Mac noob, so would like to just have the drive mapped at ...
14
votes
9answers
6k views
Application for monitoring all applications that are using the internet in Mac OS X
Can anyone introduce me a Mac OS X application that monitors all network activity such as what applications are now connected to the internet and how much bandwidth they use (I mean show bandwidth ...
