Slow recursion with ipv6 enabled?

[G.W. Haywood]

Hi there,

On Sat, 19 Nov 2016, Job wrote:

> on Bind 9.10 (latest version of this stable branch), i notice in
> some cases a relevant slowdown when resolving (for the first time)
> hostname, when named is launched with both ipv4 and ipv6.  It use
> recursion to fetch for the first time the information and i have,
> often, about 2000/3000ms of slowdown.  Then, when record is in
> cache, it is fast.
> 
> By launching Bind with only ipv4 (-4 switch) also recursion is very fast.
> 
> Do you think there are some known issues or i have to refine my configuration?

In a case like this I'd run tcpdump and look at the packets directly.
You might see IPv6 queries to which there are no responses, resulting
in timeouts, followed by IPv4 queries for the same information.

-- 

73,
Ged.