[Blink] DNS error
jnielsen at socialserve.com
Wed Dec 12 00:35:48 CET 2012
On Dec 11, 2012, at 6:07 AM, Adrian Georgescu <ag at ag-projects.com> wrote:
> When DNS lookups using the system provided resolver fail, Blink automatically fails over to use the public Google DNS servers. This solves connectivity issue for many users that have DNS resolvers in their routers incapable of returning NAPTR and SRV records, unfortunately a large occurrence. This is why Blink just works and nobody has issues with locating the SIP servers without any special settings in the client.
Having a DNS server that has nothing to do with our (or any enterprise user's) infrastructure hard-coded in to the client is broken. Will you please expose this as a per-account advanced setting in a future release? "Backup DNS Server" or similar. Having it default to Google's for the reasons above is fine; maybe also include some explanatory text recommending against changing or removing it unless you know what you are doing, but let advanced/enterprise users control this behavior.
> In your case it Blink should not try use Google at all as its is blocked anyway and it will fail as well. But Blink cannot do such investigations in the network like you did. The software cannot guess all adverse situations it faces and there are always situations like yours where you explicitly install firewall rules that miss behave.
The client should be robust enough to at least retry DNS lookups if they fail the first time, for whatever reason. Obviously we want to find out why DNS fails more often than it should in our environment and fix that too, but surely you can concede that ALL network software should deal with transient failures as gracefully as possible, since they happen for a variety of reasons.
Thank you for the explanation.
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