Is sariki calculated by the number of grains or by the number of
according to the latest run score data, the single core run score is 5472, and the multi-core run score is 13769. In fact, there is not much concept in such a number, but the gap can only be known by comparing this year's Xiaolong 855. The actual score of snapdragon 855 processor is 2418 for single core and 9703 for multi-core, which is the most powerful flagship processor in Android Market. However, apple A13 bionic is still much stronger, completely destroying all flagship chips in the instry, including the upcoming Kirin 990
it can also be said that many domestic manufacturers are silent when they see a series processors. Indeed, Apple has always been the king of performance. The performance of the mobile phone is always higher than that of other manufacturers, but the disadvantage of Apple's mobile phone is also quite fatal, that is 5g. After all, everyone knows that 5g era is coming soon. When all other manufacturers start to follow up 5g, Apple's lack of this function is equivalent to losing most of the market
now Apple has lowered the price of the iPhone 11 series in order to make way for 5g, and such a price has attracted the attention of many netizens, which has indeed ushered in a good result. It depends on whether the sales of Apple's mobile phone can continue this time
the role of MAC address
IP address is like a position, and MAC address is like a talent to apply for this position. The position can let both a and B sit. In the same way, IP address of a node is not required for network card, and can be used by any manufacturer, That is to say, there is no binding relationship between IP address and MAC address. The mobility of some computers is relatively strong. Just as the same person can work for different units, the mobility of talents is relatively strong. The corresponding relationship between position and talent is a bit like the corresponding relationship between IP address and MAC address. For example, if a network card is broken, it can be replaced without obtaining a new IP address. If an IP host moves from one network to another, it can be given a new IP address instead of a new network card. Of course, only this function of MAC address is not enough. Take human society and network for analogy. Through analogy, we can find the similarities and better understand the role of MAC address
the communication between computers in local area network or wide area network is that data packets are transmitted from one node to another and finally to the destination node. ARP (address resolution protocol) is responsible for mapping IP address to MAC address to complete the packet movement between these nodes. In fact, human society and the Internet are similar. If a wants to take a message to D in the interpersonal network, he will transfer it through B and C, and finally C will transfer it to d. In the network, this message is like a packet in a network. In the process of data packet transmission, the MAC address of adjacent nodes will be asked constantly. This process is like the process of message transmission in human society. I believe that through these two examples, we can further understand the role of MAC address
MAC address related commands and software
in social interaction in human society, we know a person will only know his name, and ID number in general interpersonal communication will be ignored. Similarly, in the network, we often only know the IP address of colleagues or netizens, and will not care about each other's MAC address too much. To grow into a network expert, we can use some methods to understand each other's MAC address. This paper introces two common methods, winipcfg in Windows 9x and ipconfig - all in Windows 2000 / XP
only one MAC address can be obtained by using the command, and it is very troublesome to use. For network managers, we hope to have a simple operation software, we can use the "MAC scanner" to obtain MAC addresses remotely in batch. It is a network management software used to obtain the physical address of remote computer network card in batch. The software runs on a machine in the network (LAN or Internet). It can monitor the connection of the whole network, detect the IP, MAC, host name and user name of each user in real time, and record them for query. Users can make notes by themselves; It can scan across network segments, compare with the IP and MAC addresses in the database, and give an alarm for those who modify IP or use false MAC addresses
change the MAC address
generally, the MAC address is fixed in the network card. Of course, some network experts will try to modify their own MAC address. There are two ways to modify your Mac address, one is hardware modification, the other is software modification
the hardware method is to directly operate the network card, modify the MAC address stored in the EPROM of the network card, and change the address in the memory through the modification program provided by the network card manufacturer. So what is EPROM? EPROM is a professional term of memory in electronics. It is erasable. That is to say, you can't use the eraser to erase a piece of white paper after you write it with a pen. However, EPROM can be erased again after you write it with a pencil, and the data storage device can be changed repeatedly
of course, the method of software modification is relatively much simpler. In windows, the MAC of network card is saved in the registry, and the actual use is extracted from the registry, so you can change the MAC as long as you modify the registry. Modify in Windows 9x: open the registry editor, in HKEY_ LOCAL_ MACHINE\ SYSTEM\ CurrentControlSet\ < br />Service\ Class\ Net\ Under the table
modification in Windows 2000 / XP: also open the registry editor, HKEY_ LOCAL_ MACHINE\ SYSTEM\ CurrentControlSet\ Control\ < br />Class\ In 4d36e970-e325-11ce-bfc1-08002be10318, if the driverdesc in 000000010002 is found in 0000, add a string variable named "networkaddress" under 0000, and the value is the MAC address to be set, for example: 000102030405
restart after completing the above operation. Generally, the source MAC address of the packet sent by the network card is not written by the network card itself, but provided by the application program. Only in the normal implementation, the application program gets the MAC address from the network card first, and uses this MAC as the source MAC every time it sends. The MAC address in the registry is read from the network card when windows is installed, As long as your operating system is not re installed, it should not be a problem<
Application of MAC address
the role of ID card on weekdays is not very big, but at some critical moments, ID card is used to prove your identity. For example, if you want to withdraw cash from the bank, you need to use your ID card. So the binding of MAC address and IP address is the same reason that we carry our ID card to do important things in our daily life. Sometimes, in order to prevent the IP address from being embezzled, we can simply bind the switch port (the MAC table of the port uses static entries) to prevent the embezzlement of modifying the MAC address when each switch port is connected to only one host. If it is a layer 3 device, we can also provide the binding of switch port / IP / Mac to prevent the embezzlement of modifying the MAC IP address. Generally, the binding MAC address is configured on the switch and router, which is only accessible to the network management personnel. For the general computer users, as long as they understand the role of binding, it is OK. For example, if you change your laptop to another dormitory in the campus network, you will not be able to access the Internet. This is caused by the binding of MAC address and IP address (port)
security issues related to MAC address
from the above introction, we can know that this identification method is only based on MAC address. If someone can change MAC address, they can steal ip free internet access. At present, the free internet access method of stealing MAC address for cell broadband is based on this idea. If you want to steal someone's IP address, you need to know the corresponding MAC address in addition to the IP address. For example, to get the MAC address of a host in the LAN, for example, if you want to get the MAC address of a host named target in the LAN, first use the ping command: Ping target, so that the target address and MAC mapping records will be left in the ARP table cache of our host, and then query the ARP table through the ARP a command to get the MAC address of the specified host. Finally, use ARP - s IP network card MAC address, command to map the gateway IP address and its MAC address
if you want to get the MAC addresses in other network segments, you can use tool software. I think the tool that comes with windows optimization master is good. Click "system performance optimization" → "system security optimization" → "additional tools" → "cluster Ping" to scan out the MAC addresses in batches and save them to a file
tips: ARP (address resolution protocol) is an address resolution protocol. ARP is a protocol that converts IP addresses into physical addresses. There are two ways to map from IP address to physical address: tabular and non tabular. ARP is to resolve the address of the network layer (IP layer, which is equivalent to the third layer of OSI) to the MAC address of the data connection layer (MAC layer, which is equivalent to the second layer of OSI). ARP protocol obtains MAC address through IP address
arp principle: if a machine a wants to send a message to host B, it will query the local ARP cache table and find the MAC address corresponding to B's IP address before data transmission. If not, broadcast a ARP request message (carrying IP address ia of host a -- physical address PA), and request host B with IP address IB to answer physical address Pb. All hosts including B receive ARP requests, but only host B recognizes its own IP address, so it sends back an ARP response message to host a. It contains the MAC address of B. after a receives the response from B, it will update the local ARP cache. Then, the MAC address is used to send data (the MAC address is attached by the network card). Therefore, the ARP table of local cache is the basis of local network circulation, and the cache is dynamic. ARP table: in order to recall the speed of communication, the conversion of commonly used MAC address and IP does not rely on the switch. Instead, an ARP table is established on the local computer to record the IP-MAC mapping table of commonly used hosts, that is, ARP table
how to solve the security problem caused by MAC address
we can bundle IP address and MAC address to solve this problem. Enter "MS-DOS mode" or "command prompt" and enter the command: ARP - s 10.88.56.72 00-10-5c-ad-72-e3 at the command prompt to bind the MAC address and IP address together. In this way, the IP address will not be stolen and can not be used normally, which can effectively ensure the security of the community network and the application of users
note: ARP command is only useful for LAN proxy server, and it is for static IP address. If modem dial-up or dynamic IP address is used, it will not work
however, simply binding IP and MAC addresses can not completely solve the problem of IP embezzlement. As a network provider, they have the responsibility to solve these problems for users before they give them to use, rather than to solve the security problems for users. Users should not be allowed to bear the loss of unnecessary embezzlement
as a network provider,
What is static IP and what is dynamic IP
static IP
there are millions of hosts on the Internet. In order to distinguish these hosts, people assign each host a special address, which is called IP address. Each host can be accessed through IP address. The IP address consists of four parts, each part corresponding to eight binary digits, and each part is separated by a decimal point. For example, the IP address of a host is 211.152.65.112, and the NIC (Internet Network Information Center) is responsible for the planning and management of the global address; At the same time, the three network information centers of inter NIC, APNIC and rip are responsible for the IP address allocation in the United States and other regions
fixed IP: a fixed IP address is an IP address assigned to a computer for a long time. Generally, a special server has a fixed IP address
dynamic IP: e to the shortage of IP address resources, users who access the Internet through telephone dial-up or ordinary broadband generally do not have a fixed IP address, but an ISP dynamically allocates a temporary IP address. Ordinary people generally do not need to understand the dynamic IP address, these are automatically completed by the computer system
the public address is in the charge of Internet Network Information Center. These IP addresses are assigned to the organizations that register and apply to the inter NIC. Direct access to the Internet through it
private address is a non registered address, which is specially used for internal use of organizations
the internal private addresses are listed below
class a 10.0.0 -- 10.255.255.255
class B 172.16.0.0 -- 172.31.255.255
class C 192.168.0.0 -- 192.168.255.255
dynamic IP
computers that access the Internet through modem, ISDN, ADSL, wired broadband, Cell Broadband, etc., have different IP addresses assigned each time, which is called dynamic IP address. Because IP address resources are very valuable, most users access the Internet through dynamic IP address. Ordinary people generally do not need to understand the dynamic IP address, these are automatically completed by the computer system
through the above description, we can roughly understand the difference between static IP and dynamic IP<
let's get down to business:
compile VI / etc / sysconfig / network scripts / ifcfg-eth0 file, set IP address, subnet mask, and gateway
& amp; lt; pre name=" code" class=" java"& amp; gt; DEVICE=eth0
HWADDR=00:0C:29:73:09:46
TYPE=Ethernet
UUID=096eb8aa-af16-4032-a6b9-40d015ea663d
ONBOOT=yes
NM_ CONTROLLED=yes
BOOTPROTO=static
IPADDR=192.168.46.98
NETMASK=255.255.255.0
GATEWAY=192.168.46.254& lt;/ pre& gt;
it should be noted that when the bridging mode is used, the subnet mask and gateway, IP address and network segment should be consistent with those on Win:
if there is no gateway, the corresponding gateway address should be configured:
& amp; lt; pre name=" code" class=" java"& amp; gt;[ root@ganglia ~]# cat /etc/resolv.conf
search searchcn.msf
nameserver 192.168.32.2
nameserver 202.106.0.20
[ root@ganglia ~]# & lt;/ pre& gt;
finally, restart the network, Ping some Internet addresses, and test whether it passes
here are some network commands:
& amp; lt; pre name=" code" class=" java"& amp; gt; Ifdown eth0 / / turn off the network
ifconfig eth0 down / / turn off the network
ifup eth0 / / turn on the network
ifconfig eth0 up / / turn on the network
service network start / / start the network service
Service network stop / / stop the network service
service network restart / / restart the network service
service network status / / view the network service status
ifconfig - A //View parameters of all network cards & amp; lt;/ pre& gt;< br />