/** * Get local IP address * @author YOLANDA * @return */public static string Getlocalipaddress () {String ipAddress = ""; try {Enumerat ion/* here to add a little explanation, because at the beginning of 21, HttpClient was abandoned, Google recommended the use of Urlconnect, where the Ipv4 is also abandoned, in order to be compatible with later versions, I httpclient some of the source code directly to the
/28,3.4.5.6/32, and these keys are used as IP expressions, The difference is that they only consider some contiguous bits in 32 bits and not necessarily all, we will find that for the 32-bit prefix of the route key, they correspond to some nodes of the lowest leaf node, and for the less than the 32-bit prefix of the route key, they correspond to some intermediate nodes. So we got a new tree based on the
five RIR regions
Although some technical measures (suchNAT technology, I willArticleIn-depth Nat)This slows down the urgency of the situation, but the IPv4 addressDepletionThe day will soon come. Obviously, we need more IP addresses to meet the needs of the explosive growth of internet devices.
Too much stuff for IPv4
Longer = better
The most important improvement of IPv6 addresses is:Lengt
Internet and each host is assigned a logical address common IP address, divided into IPv4 and IPv6 two major categories. IPV4 addresses are usually expressed as "dotted decimal" (a.b.c.d), where a,b,c,d are 0~255 decimal integers IPv4 a
IPv4 address depletion crisis needs to be sent to IPv6 as soon as possible
IP address is an important part of the IP protocol. It can identify any device connected to the Internet. In the IP address relay, we can see that the IP address of the IP packet is written in the he
Public Static String Getlocalip (){ Try { String Hostname = DNS. gethostname (); // Get the Host Name Iphostentry ipentry = DNS. gethostentry (hostname ); For ( Int I = 0 ; I { // Select an IPv4 IP address from the IP address list. // Addressfamily. Internetwork indicates that the IP address is
Public static string getlocalip (){Try{String hostname = DNS. gethostname (); // obtain the host name.Iphostentry ipentry = DNS. gethostentry (hostname );For (INT I = 0; I {// Filter IPv4 IP addresses from the IP address list// Addressfamily. Internetwork indicates that the IP address is IPv4,// Addressfamily. internet
address number of Address block first address See below : three steps 1. The address number of the address block N can be used n=2 32-n The second side to find out .2. Ask for first address , We keep the left n po
Start from Windows VistaIPv6 is enabled by default.In the environment where both IPv4 and IPv6 coexist, IPv6 has a high priority. Therefore, the obtained IP address is in the IPv6 format. Fortunately, to solve this problem, you do not have to deliberately disable IPv6. The same problem is the parsing of localhost in the host file. The IPv6 address is returned by
IPV4 Multicast (multicast) mechanism refers to: the mechanism of sending and receiving IP multicast traffic. IP multicast traffic is sent to a single destination IP address, but is received and processed by multiple IP hosts, regardless of where the host is located on the IP internetwork. A host listens on a specific IP multicast address and receives all packets
IPV4
and
IPV6
address
ObjectiveYesterday, the computer let others speed limit,I had a nightmare last night.,should I learn some cyber-security knowledge?,that way.,I don't invade people.,people invade me .,and I can protect myself .,Actually, if everyone is okay,,Don't you mess with me .,I'm not messing with you.,I
I've been dealing with IP addresses for a few days. GdB comes out with a variable, go to the calculator to look at the binary, and then every eight bits to calculate the IP address, really patience. Searched the information on the Internet, and did not find a similar tool. Maybe everyone thinks it's too easy to write such a thing. but actually, Whether it is simple or not, it is a good command to actually p
is addition. That is to say, if all the bytes remain unchanged, you can simply add a power value of 2 to each position. For example, if we have an 8-digit 11111111, we can simply add: 27 + 2 6 +2 5 + 2 4 + 2 3 + 2 2 + 2 1 + 2 0 = 255
Now we try to understand an extraordinary example: 11110000
We can see that four of the above eight digits are "fixed ". Add the 2's power to these positions. The result is 27 + 26 + 2 5 + 2 4 = 240.
This is simple. If you can convert a binary number to a decimal n
The power of netizens is strong. Yesterday I posted a post about an interview/PEN question. It provides many solutions for netizens. I have to admit that I wroteCodeIs so bad. Even so, it is also necessary to discuss with everyone, it is also necessary to write your own thoughts. Only in this way can we make progress and make changes to optimize our bad code. Then I sent a piece of bad code, hoping to learn more beautiful and excellent code from netizens.
Test Questions
Determines whet
Disable Automatic ipv4 Address Configuration for win7 and disable win7ipv4Symptom
A new computer is connected to a network cable without dhcp. You need to manually configure the Ip address.
After an Ip address is configured, the ping gateway fails.
Two IP addresses are found in ipconfig:
Automatically configure the
Today to set up a good IP company, no matter how it is not on the Internet, once again opened local found that the default gateway automatically disappeared, CMD under the input ipconfig after the phenomenon is as follows:
Physical Address ............. : 00-22-64-55-76-8fDHCP enabled ........... : NoAutomatic configuration Enabled ..........: isAutomatic configuration IPv4
recently installed the original WIN7 system after the network card driver patch, to the computer set a fixed IP address after all normal, but the computer restarts found on the network, the bottom right corner network icon has an exclamation point, open the network and Sharing center--local connection--details --> found The address of the IPV4 with the ipconfi
Computer in use will inevitably encounter the problem of not networking, at this time need to IPv4 Internet Protocol settings, and in different operating systems to set the IPV4 mode is also different, then in Win7 flagship system how to IPV4 set to automatically obtain IP address?
Win7 flagship
After setting the IP address at the company today, you will not be able to access the Internet in any case. If you enable the local connection again, the default gateway will disappear automatically. The following figure shows how to enter ipconfig in cmd:
Physical address ......: 00-22-64-55-76-8fDHCP is enabled... noAutomatic configuration is enabled... yesAutomatically configure
This example describes the regular expression validation IPV4 address feature. Share to everyone for your reference, as follows:
The IPV4 address consists of 4 groups of numbers, separated by a., and the range of values for each group of numbers is 0-255.
IPV4 must meet the
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