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540

Everybody is over-complicating it with RFCs, IP classes, and such. Simply run a few tests to see how the ping command parses the IP input by the user (extraneous chaff removed): > ping 1 Pinging 0.0.0.1 with 32 bytes of data: > ping 1.2 Pinging 1.0.0.2 with 32 bytes of data: > ping 1.2.3 Pinging 1.2.0.3 with 32 bytes of data: > ping 1.2.3.4 ...


141

There are two reasons for this: First, a '0' prefix indicates an octal number. Since oct(072) = dec(58), 192.168.072 = 192.168.58. Second, the second-to-last 0 can be dropped from IP addresses as a shorthand. 127.0.1 is interpreted as 127.0.0.1, and in your case 192.168.58 is interpreted as 192.168.0.58.


116

What's the difference between 127.0.0.1 and 0.0.0.0? 127.0.0.1 is the loopback address (also known as localhost). 0.0.0.0 is a non-routable meta-address used to designate an invalid, unknown or non applicable target (a no particular address placeholder). In the context of a route entry, it usually means the default route. In the context of servers,...


95

They are not the same. 127.0.0.1 is part of the 127/8 network which is reserved and points to the same computer. 0.0.0.0 is a special IP address that means different things depending on context. In the Internet Protocol Version 4, the address 0.0.0.0 is a non-routable meta-address used to designate an invalid, unknown or non-applicable target. To ...


94

In addition to @neu242's important point about octal notation, and observation that IP addresses can be shortened, the other critical piece is knowing how shortened IP addresses are interpreted. One might naively guess that if some of the four numbers are missing, the parser would add zero-filled bytes onto the end (or the beginning) of the sequence of ...


73

I know who chose these address ranges. Unfortunately, he is dead, so I cannot ask him exactly why he chose them, but I can make some well informed guesses. There isn't much online dating prior to the mid-1990s, when the Internet really started to take off. What history of the Internet exists is mostly in the RFCs which define it, which date back to 1969, at ...


70

There's specifically a blackhole prefix in IPV6, as described in RFC 6666, it's 100::/64. IP4 does not have an explicit black hole like that, but a non-existent host on one of the reserved blocks would have that effect. (e.g., 240.0.0.0/4 is "reserved for future use" and will not be routed by anything.)


53

Type this into a .bat file. You can then create a shortcut to it and place it in the taskbar, start menu, or assign a hotkey. ipconfig | find "IPv4" | find /V "192.168." | CLIP What it does: First find returns all the lines that contain IPv4. If you have multiple network adapters, from example from VMWare, you may want to exclude them. That's where find /...


52

It's not MS it is the ISOC ;-) Have a look at reserved IP address RFC 5735 under special use IPv4: here 169.254.0.0/16 - This is the "link local" block. As described in [RFC3927], it is allocated for communication between hosts on a single link. Hosts obtain these addresses by auto-configuration, such as when a DHCP server cannot be ...


48

A machine with machine name "accounting" and ip "192.168.1.95" IP -> Machine Name: tracert 192.168.1.95 or NBTSTAT -a 192.168.1.95 Machine Name -> IP nslookup accounting or ping accounting


45

On Windows CMD if you put leading zeros on the IP address means octal. It is interpreting 016 as 16 octal and converts it to 14 decimal. You can use octal, decimal or hexadecimal notation as in the following example: 22.101.31.153 (decimal) 026.0145.037.0231 (octal) 0x16.0x65.0xF1.0x99 (hexadecimal)


42

You are not pinging the same interface, without any physical interfaces you still have a "local host". Your localhost is used to refer to your computer from its "internal" IP, not from any "external" IPs of your computer. So, the ping packets don't pass through any physical network interface; only through a virtual loop back interface which directly sends ...


41

The use of 169.x.x.x addresses are defined within a standard colloquially known as APIPA - Automatic Private IP Addressing. In a nutshell, if a network device has not been assigned a fixed (static) address and cannot obtain one by asking (DHCP), the device says to itself, "Well, I'd better make up an address of my own so I can communicate on this network", ...


34

There is such a thing as network Black hole. If there are no devices in the network with IP address 192.168.0.10, then this IP address is kind of black hole and it will "discard" all the traffic to it, simply because it does not exist. Protocols which keep track of connection state (TCP) can detect a missing destination host. It will not happen with UDP ...


31

Nmap is available for Windows: # nmap -sP 10.0.10.1-100


31

I wonder what each interface is. lo0 = loopback gif0 = Software Network Interface stf0 = 6to4 tunnel interface en0 = Ethernet 0 fw0 = Firewire en1 = Ethernet 1 vmnet8 = Virtual Interface vmnet1 = Virtual Interface Something like that. Also, which of these is the IP interface ? There hasn't been "the" IP interface since many years ago. All of them ...


30

I'm a forensics major, and I'd say "no, not really". I'm assuming you're looking at the header and the information from there. Its painfully simple to run things through a proxy to hide your actual IP address. There's a few possible scenarios here - lets talk about the most obvious - he's using a proxy service, tunneling things through there and the ip ...


30

Because it made sense at the time? :-D Remember, back when the private IP address ranges were assigned, there were several issues network engineers had to contend with: Some of the most powerful routers at the time had about as much CPU power and RAM storage as today's pocket graphing calculators--and some of the ones today still run circles around yester-...


29

When using DHCP, the (Wi-Fi) router is the DHCP server, that is, the network host that assigns the IP addresses. The computers do not choose their address from the pool; the router chooses and tells the computer what its address will be. Therefore, you have two options if you want a computer to always have the same IP address: Option 1: IP address ...


28

You have to Google for "free http proxy", some of the lists you get as a result classify geographically the proxies, find one of those and then choose a US located proxy. Afterwards set your browser to use as HTTP proxy your selected proxy (what are the steps to do this depends on the browser you use). Some proxies work better than others and some just don'...


28

try this: grep -E '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' /etc/hosts which matches all expressions from 0.0.0.0 to 999.999.999.999 with grep -Eo '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' /etc/hosts you will get IP addresses only note: on solaris probably egrep will do the job.


28

The different networking layers are there to allow them to be swapped for different technologies. The two layers you are talking about here are layers 2 and 3. Layer 2 in this scenario is Ethernet - from which MAC addresses arise, and Layer 3 is IP. Ethernet only works at the local level, between network devices connected to a broadcast network "datalink",...


27

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 would not be possible.


27

Yes: http://en.wikipedia.org/wiki/Loopback The most commonly used IP address on the loopback device is 127.0.0.1 for IPv4, although any address in the range 127.0.0.0 to 127.255.255.255 is mapped to it. or from the RFC itself: RFC 3330 - Special-Use IPv4 Addresses 127.0.0.0/8 - This block is assigned for use as the Internet host loopback ...


26

Spoofing your IP address in the manner you are describing is like writing the wrong return address on an envelope and expecting a reply letter to your real address. It isn't going to happen because the only reply information they have is the wrong return address. There are many Linux tools that will let you create spoofed IP datagrams, and with iptables ...


25

You have to consider also that an ip can be represented by integers added together in significance to their position. 192.168.0.58 is : 192 * 256^3 + 168 * 256^2 + 0 * 256^1 + 58 * 256^0 Here's the cool thing: 192.168.58 will be 192.168.0.58 because 0 * 256^1 + 58 * 256^0 = 58 192.11010106 will also be 192.168.0.58 because 168 * 256^2 ...


23

Yes, you can (sometimes) resolve an IP Address back to a hostname. Within DNS, an IP Address can be stored against a PTR record. You can use nslookup to resolve both hostnames and IP addresses, though use of nslookup has been deprecated for quite some time. For best results, you should really get a hold of the dig tool. If you're a linux user, this is ...


22

Create a shortcut to BGinfo (a program that shows system information on the Windows background). Double-click. : )


21

The quickest way is to use Angry IP Scanner I use it for the same way you want to!


20

For ICMP query/reply type messages like Echoes (pings), NAPT uses the ICMP Query ID (sometimes just called the ICMP ID) the same way it would use a TCP or UDP port number. For ICMP error messages such as Destination Unreachable, it uses the ICMP packet's internal copy of the headers of the frame that caused the error to figure out which mapping in the NAT ...



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