[asterisk-users] is DNS SRV enough for failover?

[Alex Balashov]

Nhadie wrote:
> hi,
> 
> i'm using DNS SRV for failover, i tried to test shutting the server 
> down, sip client should still register on the other server but it did 
> not.  i'm using x-lite which i don't know if it's doing a srv query. 
> does this mean SRV is not enough for failover? if a client has dns 
> caching would this cause a problem?

SRV records are DNS.  DNS is cached.  Ergo, SRV records are cached. 
Ergo, if they are cached excessively - either because the TTL is long, 
or in defiance of the TTL - it can cause a problem.

No, DNS is not a good way to do real-time failover for anything.

-- 
Alex Balashov
Evariste Systems
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