公用ip地址查詢
What exactly is preventing you (or anyone else) from changing their IP address and causing all sorts of headaches for ISPs and other Internet users?
到底是什么在阻止您(或其他任何人)更改其IP地址并導致ISP和其他Internet用戶感到頭疼？
Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites.
今天的“問答”環節由SuperUser提供，它是Stack Exchange的一個分支，該社區是由社區驅動的Q＆A網站分組。
問題 (The Question)
SuperUser reader Whitemage is curious about what’s preventing him from wantonly changing his IP address and causing trouble:
超級用戶讀者Whitemage很好奇為什么阻止他大肆更改IP地址并造成麻煩：
An interesting question was asked of me and I did not know what to answer. So I’ll ask here.
問了一個有趣的問題，我不知道該怎么回答。 所以我會在這里問。
Let’s say I subscribed to an ISP and I’m using cable internet access. The ISP gives me a public IP address of 60.61.62.63.
假設我訂閱了ISP，并且正在使用有線互聯網訪問。 ISP給了我一個公共IP地址60.61.62.63。
What keeps me from changing this IP address to, let’s say, 60.61.62.75, and messing with another consumer’s internet access?
是什么讓我無法將此IP地址更改為60.61.62.75，并弄亂了另一個消費者的互聯網訪問權限？
For the sake of this argument, let’s say that this other IP address is also owned by the same ISP. Also, let’s assume that it’s possible for me to go into the cable modem settings and manually change the IP address.
為了這個論點，假設另一個IP地址也由同一ISP擁有。 另外，假設我可以進入電纜調制解調器設置并手動更改IP地址。
Under a business contract where you are allocated static addresses, you are also assigned a default gateway, a network address and a broadcast address. So that’s 3 addresses the ISP “loses” to you. That seems very wasteful for dynamically assigned IP addresses, which the majority of customers are.
在為您分配了靜態地址的商業合同下，還為您分配了默認網關，網絡地址和廣播地址。 這樣就可以解決ISP向您“丟失”的3個問題。 對于大多數客戶都是動態分配的IP地址，這似乎非常浪費。
Could they simply be using static arps? ACLs? Other simple mechanisms?
他們可以簡單地使用靜態arps嗎？ ACL？ 其他簡單的機制？
Two things to investigate here, why can’t we just go around changing our addresses, and is the assignment process as wasteful as it seems?
這里有兩件事情需要調查，為什么我們不能只是四處更改地址，分配過程看起來是否很浪費？
答案 (The Answer)
SuperUser contributor Moses offers some insight:
超級用戶貢獻者Moses提供了一些見解：
Cable modems aren’t like your home router (ie. they don’t have a web interface with simple point-and-click buttons that any kid can “hack” into).
電纜調制解調器不像您的家用路由器(即，它們不具有帶有簡單的點擊按鈕的Web界面，任何孩子都可以“點擊”)。
Cable modems are “looked up” and located by their MAC address by the ISP, and are typically accessed by technicians using proprietary software that only they have access to, that only runs on their servers, and therefore can’t really be stolen.
ISP會“查找”電纜調制解調器并按其MAC地址定位電纜調制解調器，技術人員通常使用專有軟件訪問它們，這些專有軟件只有他們可以訪問，只能在其服務器上運行，因此實際上無法被盜。
Cable modems also authenticate and cross-check settings with the ISPs servers. The server has to tell the modem whether it’s settings (and location on the cable network) are valid, and simply sets it to what the ISP has it set it for (bandwidth, DHCP allocations, etc). For instance, when you tell your ISP “I would like a static IP, please.”, they allocate one to the modem through their servers, and the modem allows you to use that IP. Same with bandwidth changes, for instance.
電纜調制解調器還通過ISP服務器驗證和交叉檢查設置。 服務器必須告訴調制解調器其設置(和電纜網絡上的位置)是否有效，并且只需將其設置為ISP為其設置的設置(帶寬，DHCP分配等)即可。 例如，當您告訴您的ISP“請給我一個靜態IP。”時，他們通過服務器將一個IP分配給調制解調器，而調制解調器則允許您使用該IP。 例如，與帶寬更改相同。
To do what you are suggesting, you would likely have to break into the servers at the ISP and change what it has set up for your modem.
要執行您的建議，您可能必須闖入ISP的服務器并更改為調制解調器設置的內容。
Could they simply be using static arps? ACLs? Other simple mechanisms?
他們可以簡單地使用靜態arps嗎？ ACL？ 其他簡單的機制？
Every ISP is different, both in practice and how close they are with the larger network that is providing service to them. Depending on those factors, they could be using a combination of ACL?and?static ARP. It also depends on the technology in the cable network itself. The ISP I worked for used some form of ACL, but that knowledge was a little beyond my paygrade. I only got to work with the technician’s interface and do routine maintenance and service changes.
每個ISP在實踐上以及與提供服務的較大網絡之間的距離都不同。 根據這些因素，他們可能會結合使用ACL和靜態ARP。 它還取決于電纜網絡本身的技術。 我曾經工作過的ISP使用了某種形式的ACL，但是這些知識超出了我的薪水范圍。 我只需要使用技術人員的界面并進行例行維護和服務更改。
What keeps me from changing this IP address to, let’s say, 60.61.62.75 and mess with another consumer’s internet access?
是什么讓我無法將此IP地址更改為60.61.62.75，并且使另一個用戶的互聯網訪問陷入混亂？
Given the above, what keeps you from changing your IP to one that your ISP hasn’t specifically given to you is a server that is instructing your modem what it can and can’t do. Even if you somehow broke into the modem, if 60.61.62.75 is already allocated to another customer, then the server will simply tell your modem that it can’t have it.
鑒于上述情況，阻止您將IP更改為ISP未專門提供給您的IP的服務器是一臺服務器，它指示調制解調器它可以做什么和不能做什么。 即使您以某種方式闖入了調制解調器，如果60.61.62.75已經分配給另一位客戶，服務器也會簡單地告訴您的調制解調器它無法使用它。
David Schwartz offers some additional insight with a link to a white paper for the really curious:
David Schwartz提供了一些額外的見解，并提供了一個白皮書鏈接，以幫助您真正好奇：
Most modern ISPs (last 13 years or so) will not accept traffic from a customer connection with a source IP address they would not route to that customer were it the destination IP address. This is called “reverse path forwarding”. See?BCP 38.
大多數現代ISP(最近13年左右)都不接受來自具有源IP地址的客戶連接的流量，如果源IP地址是源IP地址，則它們將不會路由到該客戶。 這稱為“反向路徑轉發”。 參見BCP 38 。
Have something to add to the explanation? Sound off in the the comments. Want to read more answers from other tech-savvy Stack Exchange users??Check out the full discussion thread here.
有什么補充說明嗎？ 在評論中聽起來不對。 是否想從其他精通Stack Exchange的用戶那里獲得更多答案？ 在此處查看完整的討論線程。
翻譯自: https://www.howtogeek.com/174306/what-keeps-you-from-changing-your-public-ip-address-and-wreaking-havoc-on-the-internet/
公用ip地址查詢
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