380

Preface: There has been much discussion in comments and other answers about how to interpret the term "Wi-Fi"; what it should or does mean by virtue of historical and common usage and implied meaning. There is no "right answer" to that. This answer can only address what the term is officially supposed to mean, and the historical ...


249

802.11 (b/g/n) operates on the 2.4 GHz ISM band. This is conveniently the same band that your microwave oven operates on. This isn't a coincidence, both operate in the 2.4 Ghz ISM band, because it can be freely used at low power without licence nearly anywhere in the world. Many other RF technologies including Bluetooth, walkie talkies, baby monitors, etc. ...


218

Sam3000's answer is very nice. I'll add some technical details. Wake on Magic Packet causes the network card to awaken the computer when it receives a magic packet. A packet is considered "magic" when it contains FF FF FF FF FF FF (six instances of the largest possible byte value) followed by sixteen instances of the card's six-byte MAC address. That ...


209

You are going to laugh, but I was in the same situation. I could not find my mother-in-law's router as the cable company had installed it. When my nephews came over they wanted to use WIFI on their Samsung Tablet. I told them that the WIFI code is on a sticker at the bottom of the router. They turned the whole house upside down, and found the router on a ...


201

If you have a Android smartphone or tablet, you can use the WiFi Analyzer app. It has a screen dedicated to detecting proximity of access points: Walk around the house and see where the signal is the strongest.


150

Barring an obvious wire leading to it, then searching by WiFi signal strength should be good too. But not the "walk around blindly with a strength meter" approach, use an app that will map it for you. ekahau Heat Mapper It can make a map for you, that should give you a better idea of which corners to be concentrating your search in. It's for ...


148

Without arguing the semantics, yes the statement is true. There are multiple standards for WIFI encryption including WEP, WPA and WPA2. WEP is compromised, so if you are using it, even with a strong password it can be trivially broken. I believe that WPA is a lot harder to crack though (but you may have security issues relating to WPS which bypass this), ...


147

The other answers so far are about security, but there is another factor that may well be at least part of your trouble. A wireless network at 2.4 GHz (in Sweden where I am, using b/g/n) allows 13 channels. (My router also has an "auto" setting.) On top of that, if the router has 5 GHz Wifi there is another set of channels. I suggest you download ...


143

Disclaimer. This is very simplified explanation, mistakes are (mostly) intentional. Radiation can be separated into two categories: ionizing radiation and non-ionizing radiation. In layman terms, ionizing radiation is radiation that can "break" the molecules that make up things. Non-ionizing radiation, on the other hand, just passes through objects or is ...


130

Yes, it is most likely some kind of hacking ploy, although it's a guess as to why. I do point out that locking your router down to specific MAC addresses might provide a tiny bit of security, but not much. It's also unlikely that their actions are designed to hack your network - they are more likely to try and capture your traffic. If it were me, I ...


129

These two settings form a feature of most modern computers known as "Wake on LAN"; in a nutshell, leaving this setting on allows the network card of your system to receive sufficient power to remain in standby mode, while the rest of the system is powered off. While in standby mode, it may receive a "magic packet" - a small amount of data specific to the mac ...


112

Wi-Fi is half duplex and has more overhead than Ethernet, so you never see TCP/IPv4 thruput even as high as 80% of your physical signalling rate (known as a "PHY rate"). Plus, when sending wireless to wireless, every packet takes up channel airtime twice: once from the source to the AP, then again from the AP to the destination. So assuming both clients ...


106

Both microwaves and Wifi operate on the same frequency, 2.4 GHz. In theory, a "properly shielded" microwave shouldn't leak any radiation. However, in practice, they leak quite a bit. Here is a blog post from one of the guys over at serverfault. They took a frequency analyzer, and looked at how various other 2.4 GHz devices (like microwaves and baby ...


104

If you increase your WAN speed, your WiFi will stay the same bottleneck it is now. To improve speed "in the furthest corners" you need to improve WiFi connectivity first. Your water tap is somewhat clogged. It won't matter if you double the cross section of the pipe to the waterworks, until you fix the tap. Similar situation.


89

You're both seen as having the same IP address externally. Your router will relay requests to the originating computer. The procedure used for this is network address translation (NAT). One of the ways computers on the same network get distinguished in communication with the same public server is by assigning them by the router different port numbers in ...


80

To be completely honest the best thing to do is get some armoured CAT6 cable and do it properly. Wi-Fi might be "convenient" but over any real range it can be intermittent, affected by a whole raft of things such as weather, obstructions, interference from local devices such as microwave ovens and cordless phones and solar flares or the phase of the moon. ...


79

This serverfault answer has good high-level guidance on what to do - so start with that. That last step is a real doozy though: presumably you (I mean, me) don't want to invest in dedicated hardware for this... Below are some good tools, first for understanding connectivity health within the local wifi network, and then to an internet endpoint. Wifi Tools ...


79

Most ISP usually don't have visibility on the actual number of devices connected on your home because you are behind a router (that probably runs a NAT that assigns each of your home devices an internal IP). As far as the ISP can see, there is only 1 connection (via your router) to the ISP. How many devices behind the router is usually not visible. Unless ...


76

Perfectly safe. The term "radiation" is often used to scare people. Let's get it straight. There's two factors - frequency and intensity. Frequency has a far larger effect on how damaging radiation is. WiFi and other radio communications use a very low frequency - far below visible light. Radiation that actually causes issues, could potentially cause ...


68

The other answers have mentioned microwave leaks. For anyone concerned (even if you aren't having WiFi problems) an easy way to test this for sure is to put a working cell phone in the microwave and close the door. If possible, unplug the microwave first if you are worried about accidentally hitting any buttons and turning on the microwave with your phone ...


66

Just for clarity there are two links / connections here, not one: From your ISP to your house. It has bandwidth of 40 Mbit/s From your router to the WiFi device(s) "in the furthest corners of your apartment" It has bandwidth of 1 Mbit/s The bottleneck here is link #2. Doubling the speed of link #1 will not affect link #2 at all, unless you reduce it to ...


61

There are features in some routers that allow you to set up multiple SSID's and a wifi schedule. If your router has these features, you can set up 2 wifi networks with different SSID's and different passwords, and schedule one of them to be on and off at certain hours.


61

Good question! Basically the smartphone can't transmit a very powerful signal, but a router can "hear" a much weaker signal. Wireless communication waves don't have a hard cutoff line, they just become weaker or more distorted over distance. The more powerful a transmitter is, the farther the signal is strong enough for other devices to pick up. ...


57

This is what I use, nmap, and an address using CIDR block notation of the network you want to scan. First you need to install nmap as it may not come pre-installed with you distro. On Ubuntu: sudo apt-get install nmap Next figure out your network address by using ifconfig: ifconfig ifconfig output for the interface I want to scan: wlan1 Link encap:...


57

That's probably a 2.4 GHz wireless mouse and you're probably using 2.4 GHz Wi-Fi, so your mouse is probably interfering with your Wi-Fi signals. Try changing your TP-Link router's channel and the mouse system's channel so they don't overlap. Consider switching to 5 GHz Wi-Fi or a wired USB mouse.


57

It sounds to me that this is something called "Evil Twin". Basically the attacker creates a network that mimics yours so you (or your machine all by itself) connect to that instead. He achieves that by, as davidgo said, sending de-auth packets to your router so you have to reconnect. By changing the MAC-Address of his own router to the one of yours, your ...


53

To borrow from U.S. Senator Ted Stevens, the Internet is a series of tubes. You have one tube coming into your house—the ISP connection plugged into your router. Everything behind your router shares that tube—think of the Ethernet cables as a regular straw, and the Wi-Fi as a long, flexible straw. If someone on the Ethernet straw is drinking up all the ...


52

As others have said, SSID hiding is trivial to break. In fact, your network will show up by default in the Windows 8 network list even if it's not broadcasting its SSID. The network still broadcasts its presence via beacon frames either way; it just doesn't include the SSID in the beacon frame if that option is ticked. The SSID is trivial to obtain from ...


51

Chromecast acts as an access point when first turned on. For the initial setup, you install an app on your Android, Windows or mac device, that will find it and connect to the chromecast's AP directly. Then the chromecast scans for nearby access points, allowing you to pick one and enter in its password. Once this is done, it will connect to that access ...


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