比特币unique

A. MAC 地址的前面3个字节代表什么各个字段代表什么含义

MAC是48比特长16进制的数字组成。0-23位叫做组织唯一标志符(organizationally unique，是识别LAN（局域网）节点的标识。24-47位是由厂家自己分配，其中第40位是组播地址标志位。

网卡的物理地址通常是由网卡生产厂家烧入网卡的EPROM（一种闪存芯片，通常可以通过程序擦写），它存储的是传输数据时真正赖以标识发出数据的电脑和接收数据的主机的地址。

(1)比特币unique扩展阅读：

在计算机网络中，地址一般分为MAC地址和IP地址，MAC地址由6字节组成，IP地址有IPv4地址和IPv6地址，IPv4地址四个字节组成，IPv6地址长度有128位，即16字节。在计算机科学中，地址字节不同，地址的作用是不同的，同时地址字节中不同字节含义也是不同。

B. 怎么区分PV、IV、UV

区分PV、IV、UV如下：

1、pv访问量（Page View），即页面访问量，每打开一次页面PV计数+1，刷新页面也是。

2、UV访问数（Unique Visitor）指独立访客访问数，一台电脑终端为一个访客。

3、IV是初始向量（IV，Initialization Vector）。

(2)比特币unique扩展阅读：

PV简介：

PV（page view）即页面浏览量，通常是衡量一个网络新闻频道或网站甚至一条网络新闻的主要指标。网页浏览数是评价网站流量最常用的指标之一，简称为PV。监测网站PV的变化趋势和分析其变化原因是很多站长定期要做的工作。 Page Views中的Page一般是指普通的html网页，也包含php、jsp等动态产生的html内容。来自浏览器的一次html内容请求会被看作一个PV，逐渐累计成为PV总数。

除了PV总数外，还可以从不同角度来分析和对比PV，比如想知道哪个网页(Page)被浏览的次数多就要以Page为分析对象并分别累计PV。网页一般通过URL或标题(html title)来标识，大多数工具都提供了类似的定义方法]关于PV的统计要考虑2种特殊情况：

一是从服务器返回错误网页或重定向网页时，是否计数以及如何配置；二是本地或网关服务器的缓存生效时是否计数。这些问题在实施网站分析前需要搞清楚，必要时可以咨询工具厂商。

UV简介：

UV是指不同的、通过互联网访问、浏览这个网页的自然人。

比如，在一台电脑上，哥哥打开了微软的官方主页，注册了一个会员。弟弟一会儿也看了看，注册了另一个会员。由于兄弟两个使用的是相同的计算机，那么他们的 ip是一样的，微软的官方计数器记录到一个ip登陆的信息。

但是，具有统计功能的统计系统，可以根据其他条件判断出实际使用的用户数量，返回给网站建设者真实、可信和准确的信息。比如通过注册的用户，甚至可以区分出网吧、机房等共享一个ip地址的不同计算机。

IV简介：

在有线等效保密（WEP）协议中，IV是用来和密钥组合成密钥种子，作为RC4算法的输入，来产生加密字节流对数据进行加密的。标准的64比特WEP使用40比特的钥匙接上24比特的初向量(Initialization Vector，IV) 成为 RC4 用的钥匙。

pv-网络 UV-网络 iv-网络

C. 关于MAC地址懂得进！

不在一个局域网内就没有影响。

D. 网络中mac是指什么

MAC：Media Access Control. 由于大量的计算机在以太网内“共享“数据流，所以必须有一个统一的办法用来区分传递给不同计算机的数据流的。这种问题不会发生在拨号用户身上，因为计算机会假定一切数据都由你发动给modem然后通过电话线传送出去。可是，当你发送数据到以太网上的时候，你必须弄清楚，哪台计算机是你发送数据的对象。的确，现在有大量的双向通讯程序出现了，看上去，他们好像只会在两台机器内交换信息，可是你要明白，以太网的信息是共享的，其他用户，其实一样接收到了你发送的数据，只不过是被过滤器给忽略掉了。 MAC地址是由一组6个16进制数组成的，它存在于每一块以太网卡中。 MAC地址的格式是什么？ 以太网卡的MAC地址是一组48比特的数字，这48比特分为两个部分组成，前面的24比特用于表示以太网卡的寄主，后面的24比特是一组序列号，是由寄主进行支派的。这样可以担保没有任何两块网卡的MAC地址是相同的（当然可以通过特殊的方法实现）。如果出现相同的地址，将发生问题，所有这一点是非常重要的。这24比特被称之为OUI（ Organizationally Unique Identifier）。 可是，OUI的真实长度只有22比特，还有两个比特用于其他：一个比特用来校验是否是广播或者多播地址，另一个比特用来分配本地执行地址（一些网络允许管理员针对具体情况再分配MAC地址）。 举个例子，你的MAC地址在网络中表示为 03 00 00 00 00 01 。第一个字节所包含的值二进制表示方法为00000011。可以看到，最后两个比特都被置为真值。他指定了一个多播模式，向所有的计算机进行广播，使用了“NetBEUI”协议（一般的，在Windows计算机的网络中，文件共享传输等是不使用TCP/IP协议的）。.

E. 英语高手们~~帮忙翻译一下~~

A magic race
A valiant team
A magic ring
When the dark when trying to engulf the bright
Who will save the fate of humanity?

This is a shock to many people in the film, which is my favorite film - "THE LORD OF THE RINGS". 300 million U.S. dollars of investment, nearly one in proction, representing the props, the shooting lasted for 3 years course, "The Lord of the Rings Trilogy" is a well-deserved for the Hollywood giant. I like him there are three main reasons.

He is very spectacular scenes. Very beautiful picture. "The Lord of the Rings" doomed the big screen it well. Directed by Peter seriously so often record the film - the shear rate of 150:1, actors sometimes have to rework a scene more than 30 times, more than 10,000 pieces of costumes, all equipment, weapons and different in the pursuit of the oldest feel, are the most primitive manner, by a wide variety of artisan hand-made, is unique Hobbit big feet, we must give the actors put on an hour ... ... so fine work behind the scenes, the actor is also the future work. In order to achieve the best results the film, many actors have repeatedly injured.

The story is very attractive. Occurred late in a magical world of Middle-Earth atmosphere, in order to destroy Lord of the Rings
9 envoys of different races, of mankind as a whole in order to avoid the destruction of Middle Earth Lord of the Rings and the composition of the expedition team, after the resurrection of the Solon location - Mo are moving ... ...
"The Lord of the Rings" has brought more than my visual shock, as well as the pulsating heart. Their friendship, their courage, and so many other virtues, he is deeply moving to me. He lets me know, no matter how great the difficulties encountered, as long as we have to unite to deal with the spirit of perseverance, we will prevail.

I like him, his story is not only attractive, but I like the movie the Princess of the Hon Kwok character Eowyn. The female is not only the elegance of the Princess Marie, and is an excellent female fighters. Difficult in the country at the time, decided to wear the uniform, rushed to the battlefield. Hope in the ring is about to kill the king, her fearless, in the face of the sneering ring of Hope "No man can kill me" (no man can kill me), her cool off the helmet, "I am not a man", sword Hope the results of the ring. Normal life, and did not let her become effemination to arrange the people, take care of the King, is the people's model, but also a great hero of the women's.

"The Lord of the Rings" received 11 Oscar gold is a masterpiece of film history's immortal. This is my favorite movie.

F. mac地址到底有多少位

MAC地址的长度为48位(6个字节)，通常表示为12个16进制数。

如：00-16-EA-AE-3C-40就是一个MAC地址，其中前6位16进制数00-16-EA代表网络硬件制造商的编号，它由IEEE(电气与电子工程师协会)分配，而后6位16进制数AE-3C-40代表该制造商所制造的某个网络产品(如网卡)的系列号。

形象地说，MAC地址就如同身份证上的身份证号码，具有唯一性。

(6)比特币unique扩展阅读

网卡的物理地址通常是由网卡生产厂家烧入网卡的EPROM（一种闪存芯片，通常可以通过程序擦写），它存储的是传输数据时真正赖以标识发出数据的电脑和接收数据的主机的地址。

也就是说，在网络底层的物理传输过程中，是通过物理地址来识别主机的，它一定是全球唯一的。

比如，著名的以太网卡，其物理地址是48bit（比特位）的整数，如：44-45-53-54-00-00，以机器可读的方式存入主机接口中。

以太网地址管理机构（IEEE：电气和电子工程师协会）将以太网地址，也就是48比特的不同组合，分为若干独立的连续地址组，生产以太网网卡的厂家就购买其中一组，具体生产时，逐个将唯一地址赋予以太网卡。

G. MAC地址是什么东西

MAC：Media Access Control.

由于大量的计算机在以太网内“共享“数据流，所以必须有一个统一的办法用来区分传
递给不同计算机的数据流的。这种问题不会发生在拨号用户身上，因为计算机会假定一
切数据都由你发动给modem然后通过电话线传送出去。可是，当你发送数据到以太网上
的时候，你必须弄清楚，哪台计算机是你发送数据的对象。的确，现在有大量的双向通
讯程序出现了，看上去，他们好像只会在两台机器内交换信息，可是你要明白，以太网
的信息是共享的，其他用户，其实一样接收到了你发送的数据，只不过是被过滤器给忽
略掉了。

MAC地址是由一组6个16进制数组成的，它存在于每一块以太网卡中。

MAC地址的格式是什么？

以太网卡的MAC地址是一组48比特的数字，这48比特分为两个部分组成，前面的24比特
用于表示以太网卡的寄主，后面的24比特是一组序列号，是由寄主进行支派的。这样
可以担保没有任何两块网卡的MAC地址是相同的（当然可以通过特殊的方法实现）。如
果出现相同的地址，将发生问题，所有这一点是非常重要的。这24比特被称之为OUI（
Organizationally Unique Identifier）。

可是，OUI的真实长度只有22比特，还有两个比特用于其他：一个比特用来校验是否是
广播或者多播地址，另一个比特用来分配本地执行地址（一些网络允许管理员针对具体
情况再分配MAC地址）。

举个例子，你的MAC地址在网络中表示为 03 00 00 00 00 01
。第一个字节所包含的值二进制表示方法为00000011。
可以看到，最后两个比特都被置为真值。他指定了一个多播模式，向所有的计算机进行
广播，使用了“NetBEUI”协议（一般的，在Windows计算机的网络中，文件共享传输等
是不使用TCP/IP协议的）。.

H. 每块以太网卡都有一个全球唯一的MAC地址,MAC地址由个字节组成。

由6个字节（48个二进位）组成。

MAC地址的长度是48比特（6字节），由16进制的数字组成，分为前24位和后24位。前24位叫做组织唯一标志符（Organizationally Unique Identifier，即OUI），是由IEEE的注册管理机构给不同厂家分配的代码，区分了不同的厂家。

后24位是由厂家自己分配的，称为扩展标识符。同一个厂家生产的网卡中MAC地址后24位是不同的。

MAC地址对应于OSI参考模型的第二层数据链路层，工作在数据链路层的交换机维护着计算机MAC地址和自身端口的数据库，交换机根据收到的数据帧中的“目的MAC地址”字段来转发数据帧。

(8)比特币unique扩展阅读：

作用：

在一个稳定的网络中，IP地址和MAC地址是成对出现的。如果一台计算机要和网络中另一外计算机通信，那么要配置这两台计算机的IP地址，MAC地址是网卡出厂时设定的，这样配置的IP地址就和MAC地址形成了一种对应关系。

在数据通信时，IP地址负责表示计算机的网络层地址，网络层设备（如路由器）根据IP地址来进行操作。

MAC地址负责表示计算机的数据链路层地址，数据链路层设备（如交换机）根据MAC地址来进行操作。IP和MAC地址这种映射关系由ARP（Address Resolution Protocol，地址解析协议）协议完成。

I. bt破解软件中的客户端mac是什么意思

MAC - 介质访问控制层 编辑词条
Medium Access Control的缩写，即介质访问控制层，属于OSI模型中数据链路层下层子层。
物理地址通常为MAC地址：MAC地址是烧录在Network Interface Card(网卡,NIC)里的MAC地址,也叫硬件地址,是由48比特长,16进制的数字组成。 0 -24位 由厂家自己分配。
25-47位 组织唯一标志符(organizationally unique identifier,OUI).OUI是由IEEE分配给每个组织.组织按高到低的顺序分配1个唯一的全局地址给每个网卡以保证不会有重复的编号.
第47位 indivial/Group(I/G)位,当I/G位为0的时候,我们可以设想这个地址是MAC地址的实际地址可以出现在MAC头部信息;当I/G位为1的时候,我们可以设想它为广播或多播.
第46位 G/L位,也叫U/L位.当这个位为0的时候代表它是由IEEE分配的全局地址;当这个位为1的时候,代表本地管理地址 (例如在DECnet当中)

J. 什么是Mac地址

MAC地址1212

MAC（Media Access Control, 介质访问控制）MAC地址是烧录在Network Interface Card(网卡,NIC)里的.MAC地址,也叫硬件地址,是由48比特长(6字节),16进制的数字组成.0-23位是由厂家自己分配.24-47位,叫做组织唯一标志符(organizationally unique ，是识别LAN（局域网）节点的标识。其中第40位是组播地址标志位。网卡的物理地址通常是由网卡生产厂家烧入网卡的EPROM（一种闪存芯片，通常可以通过程序擦写），它存储的是传输数据时真正赖以标识发出数据的电脑和接收数据的主机的地址。

也就是说，在网络底层的物理传输过程中，是通过物理地址来识别主机的，它一般也是全球唯一的。比如，著名的以太网卡，其物理地址是48bit（比特位）的整数，如：44-45-53-54-00-00,以机器可读的方式存入主机接口中。以太网地址管理机构(除了管这个外还管别的)（IEEE）（IEEEE：电气和电子工程师协会）将以太网地址，也就是48比特的不同组合，分为若干独立的连续地址组，生产以太网网卡的厂家就购买其中一组，具体生产时，逐个将唯一地址赋予以太网卡。

形象的说，MAC地址就如同我们身份证上的身份证号码，具有全球唯一性。

如何获取本机的MAC？

对于数量不多的几台机器，我们可以这样获取MAC地址：在Windows 98/Me中，依次单击“开始”→“运行” →输入“winipcfg”→回车。即可看到MAC地址。

在Windows 2000/XP中，依次单击“开始”→“运行”→输入“CMD”→回车→输入“ipconfig /all”→回车。即可看到MAC地址。

修改网卡MAC地址的方法

其实更改网卡MAC地址的功能不论98、2000还是XP，都已经提供了，只是平时大家都没有注意到而以。下面我就说说怎么更改。很简单哦。。。

好了，现在先来看看WIN2000。在桌面上网上邻居图标上点右键，选"属性"，在出来的"网络和拨号连接"窗口中一般有两个图标，一个是"新建连接"图标，一个是"我的连接"图标。如果你的机器上有两个网卡的话，那就有三个图标了。如果你只有一个网卡，那就在"我的连接"图标上点右键，选"属性"，会出来一个"我的连接 属性"的窗口。在图口上部有一个"连接时使用："的标识，下面就是你机器上的网卡型号了。在下面有一个"配置"按钮，点击该按钮后就进入了网卡的属性对话框了，这个对话框中有五个属性页，点击第二项"高级"页，在"属性"标识下有两项：一个是"Link Speed/Duplex Mode",这是设置网卡工作速率的，我们需要改的是下面一个"Network Address",点击该项，在对话框右边的"值"标识下有两个单选项，默认得是"不存在" ，我们只要选中上面一个单选项，然后在右边的框中输入你想改的网卡MAC地址，点"确定"，等待一会儿，网卡地址就改好了，你甚至不用停用网卡！

另外，你也可以在"设置管理器"中，打开网卡的属性页来修改，效果一样。WINXP的修改方法跟WIN2000一样。

在98下面修改和WIN2000、XP下差不多。在"网上邻居"图标上点右键，选择"属性"，出来一个"网络"对话框，在"配置"框中，双击你要修改的网卡，出来一个网卡属性对话框。在"高级"选项中，也是点击"属性"标识下的"Network Address"项，在右边的两个单选项中选择上面一个，再在框中输入你要修改的网卡MAC地址，点"确定"后，系统会提示你重新启动。重新启动后，你的网卡地址就告修改成功！！

如果你想把网卡的MAC地址恢复原样，只要再次把"Network Address"项右边的单选项选择为下面一个"没有显示"再重新启动即可。在WIN2000、XP下面是选择"不存在"，当然也不用重新启动了。

In computer networking a Media Access Control address (MAC address) or Ethernet Hardware Address (EHA) or hardware address or adapter address is a quasi-unique identifier attached to most network adapters (NIC or Network Interface Card). It is a number that serves as an identifier for a particular network adapter. Thus network cards (or built-in network adapters) in two different computers will have different MAC addresses, as would an Ethernet adapter and a wireless adapter in the same computer, and as would multiple network cards in a router. However, it is possible to change the MAC address on most of today's hardware, often referred to as MAC spoofing.
Most layer 2 network protocols use one of three numbering spaces managed by the Institute of Electrical and Electronics Engineers (IEEE): MAC-48, EUI-48, and EUI-64, which are designed to be globally unique. Not all communications protocols use MAC addresses, and not all protocols require globally unique identifiers. The IEEE claims trademarks on the names "EUI-48" and "EUI-64" ("EUI" stands for Extended Unique Identifier).
MAC addresses, unlike IP addresses and IPX addresses, are not divided into "host" and "network" portions. Therefore, a host cannot determine from the MAC address of another host whether that host is on the same layer 2 network segment as the sending host or a network segment bridged to that network segment.
ARP is commonly used to convert from addresses in a layer 3 protocol such as Internet Protocol (IP) to the layer 2 MAC address. On broadcast networks, such as Ethernet, the MAC address allows each host to be uniquely identified and allows frames to be marked for specific hosts. It thus forms the basis of most of the layer 2 networking upon which higher OSI Layer protocols are built to proce complex, functioning networks.
Contents [hide]
1 Notational conventions
2 Address details
2.1 Indivial address block
3 Bit-reversed notation
4 See also
5 References
6 External links

[edit] Notational conventions
The standard (IEEE 802) format for printing MAC-48 addresses in human-readable media is six groups of two hexadecimal digits, separated by hyphens (-) in transmission order, e.g. 01-23-45-67-89-ab. This form is also commonly used for EUI-64. Other conventions include six groups of two separated by colons (:), e.g. 01:23:45:67:89:ab; or three groups of four hexadecimal digits separated by dots (.), e.g. 0123.4567.89ab; again in transmission order.

[edit] Address details
The original IEEE 802 MAC address comes from the original Xerox Ethernet addressing scheme.[1] This 48-bit address space contains potentially 248 or 281,474,976,710,656 possible MAC addresses.
All three numbering systems use the same format and differ only in the length of the identifier. Addresses can either be "universally administered addresses" or "locally administered addresses."
A universally administered address is uniquely assigned to a device by its manufacturer; these are sometimes called "burned-in addresses" (BIA). The first three octets (in transmission order) identify the organization that issued the identifier and are known as the Organizationally Unique Identifier (OUI). The following three (MAC-48 and EUI-48) or five (EUI-64) octets are assigned by that organization in nearly any manner they please, subject to the constraint of uniqueness. The IEEE expects the MAC-48 space to be exhausted no sooner than the year 2100; EUI-64s are not expected to run out in the foreseeable future.
A locally administered address is assigned to a device by a network administrator, overriding the burned-in address. Locally administered addresses do not contain OUIs.
Universally administered and locally administered addresses are distinguished by setting the second least significant bit of the most significant byte of the address. If the bit is 0, the address is universally administered. If it is 1, the address is locally administered. The bit is 0 in all OUIs. For example, 02-00-00-00-00-01. The most significant byte is 02h. The binary is 00000010 and the second least significant bit is 1. Therefore, it is a locally administered address.[2]
If the least significant bit of the most significant byte is set to a 0, the packet is meant to reach only one receiving NIC. This is called unicast. If the least significant bit of the most significant byte is set to a 1, the packet is meant to be sent only once but still reach several NICs. This is called multicast.
MAC-48 and EUI-48 addresses are usually shown in hexadecimal format, with each octet separated by a dash or colon. An example of a MAC-48 address would be "00-08-74-4C-7F-1D". If you cross-reference the first three octets with IEEE's OUI assignments,[3] you can see that this MAC address came from Dell Computer Corp. The last three octets represent the serial number assigned to the adapter by the manufacturer.
The following technologies use the MAC-48 identifier format:
Ethernet
802.11 wireless networks
Bluetooth
IEEE 802.5 token ring
most other IEEE 802 networks
FDDI
ATM (switched virtual connections only, as part of an NSAP address)
Fibre Channel and Serial Attached SCSI (as part of a World Wide Name)
The distinction between EUI-48 and MAC-48 identifiers is purely semantic: MAC-48 is used for network hardware; EUI-48 is used to identify other devices and software. (Thus, by definition, an EUI-48 is not in fact a "MAC address", although it is syntactically indistinguishable from one and assigned from the same numbering space.)
The IEEE now considers the label MAC-48 to be an obsolete term which was previously used to refer to a specific type of EUI-48 identifier used to address hardware interfaces within existing 802-based networking applications and should not be used in the future. Instead, the term EUI-48 should be used for this purpose.
EUI-64 identifiers are used in:
FireWire
IPv6 (as the low-order 64 bits of a unicast network address when temporary addresses are not being used)
ZigBee / 802.15.4 wireless personal-area networks
The IEEE has built in several special address types to allow more than one Network Interface Card to be addressed at one time:
Packets sent to the broadcast address, all one bits, are received by all stations on a local area network. In hexadecimal the broadcast address would be "FF:FF:FF:FF:FF:FF".
Packets sent to a multicast address are received by all stations on a LAN that have been configured to receive packets sent to that address.
Functional addresses identify one of more Token Ring NICs that provide a particular service, defined in IEEE 802.5.
These are "group addresses", as opposed to "indivial addresses"; the least significant bit of the first octet of a MAC address distinguishes indivial addresses from group addresses. That bit is set to 0 in indivial addresses and 1 in group addresses. Group addresses, like indivial addresses, can be universally administered or locally administered.
In addition, the EUI-64 numbering system encompasses both MAC-48 and EUI-48 identifiers by a simple translation mechanism. To convert a MAC-48 into an EUI-64, the OUI, append the two octets "FF-FF", and then the organization-specified part. To convert an EUI-48 into an EUI-64, the same process is used, but the sequence inserted is "FF-FE". In both cases, the process can be trivially reversed when necessary. Organizations issuing EUI-64s are cautioned against issuing identifiers that could be confused with these forms. The IEEE policy is to discourage new uses of 48-bit identifiers in favor of the EUI-64 system.
IPv6—one of the most prominent standards that uses EUI-64—applies these rules inconsistently. Due to an error in the appendix to the specification of IPv6 addressing, it is standard practice to extend MAC-48 addresses (such as IEEE 802 MAC address) to EUI-64 using "FF-FE" rather than "FF-FF."

[edit] Indivial address block
An Indivial Address Block comprises a 24-bit OUI managed by the IEEE Registration Authority, followed by 12 IEEE-provided bits (identifying the organization), and 12 bits for the owner to assign to indivial devices. An IAB is ideal for organizations requiring fewer than 4097 unique 48-bit numbers (EUI-48).[4]

[edit] Bit-reversed notation
The standard transmission order notation for MAC addresses, as seen in the output of the ifconfig command for example, is also called canonical format.
However, since IEEE 802.3 (Ethernet) and IEEE 802.4 (Token Bus) send the bits over the wire with least significant bit first, while IEEE 802.5 (Token Ring) and IEEE 802.6 send the bits over the wire with most significant bit first, confusion may arise where an address in the latter scenario is represented with bits reversed from the canonical representation. So for instance, an address whose canonical form is 12-34-56-78-9A-BC would be transmitted over the wire as bits 01001000 00101100 01101010 00011110 01011001 00111101 in the standard transmission order (least significant bit first). But for Token Ring networks, it would be transmitted as bits 00010010 00110100 01010110 01111000 10011010 10111100 in most significant bit first order. If care is not taken to translate correctly and consistently to the canonical representation, the latter might be displayed as 482C6A1E593D, which could cause confusion. This would be referred to as "Bit-reversed order", "Non-canonical form", "MSB format", "IBM format", or "Token Ring format" as explained by RFC 2469. Canonical form is preferred[who?].

[edit] See also
NSAP address, another endpoint addressing scheme.
Cisco Hot Standby Router Protocol or standard alternative VRRP Virtual router rendancy protocol, which allows multiple routers to share one IP address and MAC address to provide router rendancy. The OpenBSD project has an open source alternative, the Common Address Rendancy Protocol (CARP).