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Speed up DNS lookups
Authored by: ScottTFrazer on Jun 06, '07 09:39:06AM
Note that OpenDNS, in an attempt at helping you out, directs unfound FORWARD entries to a "helper" page. This can be bad for troubleshooting and automated log processing. (Reverse DNS lookups aren't affected, however) To demonstrate, do a dig using a standard DNS server (I'll use 4.2.2.1 as an example) on a hostname that doesn't exist:
dig  @4.2.2.1 i-do-not-exist.microsoft.com
You'll notice it doesn't return a host address:
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
The same query against an OpenDNS server returns a host address that isn't associated with microsoft:
dig  @208.67.222.222 i-do-not-exist.microsoft.com

;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; ANSWER SECTION:
i-do-not-exist.microsoft.com. 0 IN      A       208.69.32.130

whois 208.69.32.130
NetRange:   208.69.32.0 - 208.69.39.255
CIDR:       208.69.32.0/21
NetName:    OPENDNS-NET-2
I had this bite me while trying to troubleshoot one our developers home VPN connections.

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Speed up DNS lookups
Authored by: ghay on Jun 06, '07 10:07:48AM
Good to note, but as with anything read the manual.
OpenDNS tries to correct typos.

http://www.opendns.com/faq/#why_is_opendns_smarter


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Speed up DNS lookups
Authored by: Baumi on Jun 06, '07 10:12:59PM

While that may be useful for normal browsing and most users, it can be an absolute no-no if you're running scripts that depend on getting correct DNS errors, e.g. for URL validation.

Not trying to bash OpenDNS here, just pointing out that, depending on your needs, there might be some caveats, because it's a system that's completely geared at making interactive use convenient, and breaks some prerequisites for automatic use in the process.



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