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197

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 ...


112

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 ...


69

Routers aren't necessary unless your traffic needs to move to a different subnet. When a computer wants to send some IP traffic to a different machine on its subnet, it needs the recipient's MAC address, since IP addresses aren't a thing at a switch's layer (Layer 2 of the OSI model). If it doesn't know the MAC address, it broadcasts an ARP request, saying ...


62

Definition of a cross over cable: A cross over cable is typically used between devices with the same type of interface (ie computer to computer, router to router, etc). Ethernet cables are usually made as an A or B type interface (which matters simply how it is wired. A crossover simply has A on one end and B on the other. What is happening: ...


25

If 2 computers are connected to the same vlan on a switch and share the same subnet mask - the switch should deliver the packet without hitting your firewall or router. You can verify this by running tracert 192.168.0.X (assuming Windows) and you should see a direct route to that system.


17

Almost certainly, the communication path would be A ↔︎ switch ↔︎ B, not going through the firewall and router. Assuming that workstations A and B have IP addresses with the same network and netmask, they should be able to interact with no router involved, because the switch knows how to forward packets. You should be able to verify that there are no ...


16

Your internal network will not be any slower due to the fact that all devices will communicate to each other directly (by ARPing and storing MAC addresses). You will be a little slower when you interface with the router (web administration, etc.), but that should not be noticeable. Traffic going through the router (such as going to the Internet) will be ...


11

Ethernet defines interfaces MDI and MDI-X. This terminology refers to variants of the Ethernet over twisted pair technology that use a female 8P8C port connection on a computer, or other network device. Ethernet over twisted pair uses 2 wires (one pair) to transmit and other 2 wires (other pair) to receive. MDI (ethernet card on a PC for example) uses ...


6

Once you put crosses into a cable you build into the cable application-specific assumptions. This is undesirable in cases where the same cable can be used for multiple applications. By making the cables straight through the same cables could be used for ethernet, phone, ISDN etc without too much confusion (there was still the issue of which pairs of pins ...


5

What does it really mean for me? for example, if my password is Blink281, what does changing the encryption type to say WPA-PSK really do? Using WPA-PSK would make your password very easy to crack: WPA-PSK is not secure (compared to WPA2 + AES) Your password is also too short and not complex enough. More about this later. WPA2 + AES is the most ...


4

If it's the internal (LAN) IP changing (which should be outside of the ISPs control), then set the camera up to have a static IP instead of using a dynamic one handled by DHCP. If it's your WAN (public) address that's changing, sign up for a Dynamic DNS (DDNS) service like No-ip, or DynDNs or alike, and start using the host/domain name they provide you ...


4

If you do not have a technical reason for having two subnets, the fix is easy. Each of your routers is performing NAT, and each has its own subnet, which is not what you want. Instead of using the second router as an actual router, just use it as a switch. Disable its DHCP and routing functionality and then use its switch (all of the non-WAN ports) to ...


4

These are just other computers that exist on your network. If you are at home, these could be family members or roommates. If your on public wifi, these would just be other users on that network. See this page on why this occurs. You can use this page if you don't want other users to view you on the network. You just need to turn internet sharing off.


3

Captive Portal detection is an OS built-in and although something you mostly see/experience on WiFi connections also works for wired connections. There is no DHCP magic going on there. See for instance https://msdn.microsoft.com/en-us/library/windows/hardware/dn408681.aspx Windows 8 and Windows 8.1 supports captive portal networks by immediately ...


3

Crossover cables redirect the output of one RJ-45 port into the input of the other RJ-45 port. If you connect the output of PC1 to the output of PC2 (With a straight cable), you won't get anywhere. Nowadays, NICs are smart enough to automatically reverse the IO pins, so you can achieve the same effect with a straight cable as you would with a crossover ...


3

Hotels cater to business guests who may need to use certain enterprise applications like VPN and VOIP. These sorts of applications often require that your computer has a public IP address with unblocked ports. As such, many hotels give you exactly that. Some hotels will actually let you choose whether you want this by asking if you want a public IP when you ...


3

When your browser requests an image for a web page, it sends with the request a header called Referer. The browser populates that header with the URL of the original page that the image is embedded on. Servers can inspect this header, and if the referer is not their own website, refuse to serve the file.


3

In theory two, but in reality, one should suffice: the one sending its ping needs to know where to send it. The recipient needs to know where to send the reply, but should already have this info based on information received from the ping. Unless, ofcourse one or more of the computers involved have the relevant entries in their arp table. Let's call the ...


3

It's because those devices are setup for WiFi-Direct. From a protocol point of view a Wi-Fi direct connection is established using already existing mechanisms in a number of steps: In a first step, the two devices that are to connect directly have to find each other. This is done by sending standard Wi-Fi probe request and response frames that ...


3

This is an unmanaged switch. Meaning it doesn't have a way to configure the switch. As configuration is needed to implement VLAN tagging (how else are you going to assign VLANs to ports?) it can't do VLAN. The switch has to be managed. Any modern managed switch is able to do it. (I have encountered hundreds of different make/models/types of switches and I ...


3

MoCA does exactly what you want. There are also flavors of HomePNA that go over coax, I believe.


3

What is donnyworld service? In the summer of 1994 DonnyWorld, Inc. created the original Real-Time Animation Chat(tm). This DOS-based client-server product, unique and ahead of its time, was marketed to operators of asynchronous dial-up on-line systems (BBS's), during the period that the Internet was in its infancy. We operated our first full-time 8-line ...


2

Donnyworld is a now dead "Animation Chat" protocol. If you want to know more, you can search the Internet Archive Wayback machine for donnyworld.com. The entry should probably be removed from /etc/services upstream, as the protocol is dead and the contact person for the entry can no longer be reached.


2

Radio interference could cause it. Microwave ovens could interfere. Also try a different WiFi channel. If most neighbors are on channel 6, try channel 11 or 1. Try a direct line-of-site from the laptop to the base station. Metal walls or walls with wires embedded in them could block the signal. Check the router's admin page to see if you are connected to ...


2

Expanding on heavyd's comment: a ransomware attack is likely to hit your client computer first (via drive-by download or something similar), and from there it can potentially encrypt anything the client computer has access to, including the NAS. Your first line of protection here is access controls: requiring a password to mount the NAS, and setting ...


2

You have to bear in mind what quicker means in terms of DNS speed. Even if there were a case for one name server being quicker than another you are looking at a few ms at the top of the session. All queries to that same address are going to come out of your computer's cache for probably the next hour or so. I've just pointed dig at both servers and done a ...


2

I experienced the same problem (on debian) and spent a whole day solving it. At the end I only could downgrade some packages (libsmbclient in particular) and the problem disappeared. Here you can find useful information on how to downgrade: http://askubuntu.com/questions/138284/how-to-downgrade-a-package-via-apt-get The exact command used to download from ...


2

You should double check that your Network Discovery is enabled. Here are the steps to turn it on (based on Windows 10): Go to Control Panel by opening Advanced sharing settings (from Start button). Type network and open Network and Sharing Center and select Change advanced sharing settings. Turn on network discovery and Save changes. See: What is network ...


2

How are those 12 bytes of silence actually sent? The 12 byes of silence are called an interpacket gap (IPG), interframe spacing, or interframe gap (IFG) The standard minimum interpacket gap is 96 bit times (the time it takes to transmit 96 bits of raw data on the medium), which is 9.6 µs for 10 Mbit/s Ethernet, 0.96 µs for 100 Mbit/s (Fast) ...


2

If you have a router for each of your lans and maybe an additional switch, you can build your own small "internet" on a dedicated lan0 network. These methods will also work with more than 2 lans: This setup could be accomplished even using basic home grade routers, as they are normally already configured for NAT (Network Address Translation) and ...



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