[sr-dev] dns_try_ipv6

[Andrei Pelinescu-Onciul]

On May 28, 2009 at 22:32, Juha Heinanen <jh at tutpro.com> wrote:
> Andrei Pelinescu-Onciul writes:
> 
>  > dst_blacklist_init=off if you want it disabled without the possibility
>  > to enable it later ar runtime.
>  > use_dst_blacklist=off, if you want to start with it disabled, but with
>  > the possibility to enable it later at runtime via rpcs
>  > (e.g. $ sercmd cfg.set_int_now core use_dst_blacklist 1 ).
>  > 
>  > Note however that the blacklist in sr is ip based and not dns based
>  > (I don't know how the blacklist worked in k).
> 
> i think i was mixing things up again.  sr variables are dst, not dns. 
> perhaps they are not same thing at all.  in k,
> 
> disable_dns_blacklist
> 
> The DNS resolver, when configured with failover, can automatically store
> in a temporary blacklist the failed destinations. This will prevent (for
> a limited period of time) openser to send requests to destination known
> as failed. So, the blacklist can be used as a memory for the DNS
> resolver.  

In sr/ser we have dns cache which caches also negative replies.

> 
> The temporary blacklist created by DNS resolver is named ??dns?? and it
> is by default selected for usage (no need use the use_blacklist())
> function. The rules from this list have a life time of 4 minutes - you
> can change it at compile time, from blacklists.h .  
> 
> Can be 'yes' or 'no'. By default the blacklist is disabled (Default
> value is 'yes').

In this case, try dns_cache_negative_ttl=0 (or you could disable the
entire dns cache with ude_dns_cache=off, but that will disable also dns
failover and in general I wouldn't recommend it).
> 
> if sip-router does not include dns blacklisting, then i can just delete
> the line, because i was turning dns black listing off in k config.
> 

Andrei