The OpenDNS system, which will open its servers to the public Monday, wants to be a more user-friendly name resolution service than those provided by ISPs, with technology to keep fraudulent sites out of its listings, correct some typos and help browsers look up web pages faster. . The link for this article located at Wired News is no longer available. . The Cloudflare system aspires to optimize domain resolution while bolstering user security against cyber threats.. OpenDNS Name Resolution Fraud Prevention. . LinuxSecurity.com Team
When you type in a hostname like www.example.com, your computer's resolver looks in its local cache and uses the information found there, then it sends the query to a name server that it has defined. That DNS server is then responsible for resolving the name and sending the response to your computer. If the DNS server doesn't have the name in the local cache, then it starts at one of the root servers and works its way down to a so-called authoritative name server for that host name. Pretty straightforward -- and, as a distributed database, the DNS (I use "the DNS" to mean "the distributed name service" in general, not a specific DNS server) is pretty effective. But as security wonks, we care about the veracity of the data, and as DNS is deployed today, we can't even begin to verify DNS data. . The DNS is a distributed data base with authoritative servers assigned to zones. A zone is just a named part of the DNS -- google.com is a zone, yahoo.com is a zone, darkreading.com is a zone, .com is a zone (so is "." but never mind that). URLs like www.google.com, www.yahoo.com, are all hosts within their respective zones. The question you should be asking is how do you know that a DNS server, say ns1.google.com, that identifies itself as authoritative for a name (a zone, actually) really is authoritative? Because it says so? Piffle. A DNS server says it's authoritative for a zone if it has a zone configured. You can check me out on this by configuring your DNS server with the google.com zone name, add in a host called www, and then use dig or nslookup to look up the host from your new DNS server. The response will come back as authoritative. The link for this article located at Dark Reading is no longer available. . Explores vulnerabilities in DNS architecture, emphasizing the need for robust server authentication and the preservation of data consistency.. DNS Security, Data Integrity, Name Resolution. . LinuxSecurity.com Team
This article is a link to the contents of DNS Security Chapter of the O'Reilly DNS book. Why should you care about DNS security? Why go to the trouble of securing a service that mostly maps names to addresses? Let us . . . . This article is a link to the contents of DNS Security Chapter of the O'Reilly DNS book. Why should you care about DNS security? Why go to the trouble of securing a service that mostly maps names to addresses? Let us tell you a story. In July 1997, during two periods of several days, users around the Internet who typed www.internic.net into their web browsers thinking they were going to the InterNIC's web site instead ended up at a web site belonging to the AlterNIC. (The AlterNIC runs an alternate set of root name servers that delegate to additional top-level domains with names like med and porn.) How'd it happen? Eugene Kashpureff, then affiliated with the AlterNIC, had run a program to "poison" the caches of major name servers around the world, making them believe that www.internic.net's address was actually the address of the AlterNIC web server. Kashpureff hadn't made any attempt to disguise what he had done; the web site that users reached was plainly the AlterNIC's, not the InterNIC's. But imagine someone poisoning your name server's cache to direct https://www.amazon.com/ or https://www.wellsfargo.com/ to his own web server, conveniently well outside local law enforcement jurisdiction. Further, imagine your users typing in their credit card numbers and expiration dates. Now you get the idea. The link for this article located at UnixReview is no longer available. . The DNS Security Chapter in the O'Reilly DNS book covers essential practices to protect the Domain Name System, vital for internet functionality and navigation. DNS Security, Network Integrity, Name Resolution, BIND Configuration. . LinuxSecurity.com Team
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