[ratelimits] CH/TXT/id.server queries rate-limited

[Anand Buddhdev]

Hi,

I've just upgraded our BIND server cluster to 9.9.2 with the rate-limit
patch. I have two questions:

a) I haven't enabled any rate-limit configuration in named.conf yet, but
now I'm seeing this in the log:

rate-limit: limit responses to x.y.0.0/16 for id.server CH TXT  (00a3d4c4)
rate-limit: limit responses to xxxx:yyyy::/32 for id.server CH TXT
(00a3d4c4)

Is this intentional?

b) One just one server, I've now activated rate limits with:

rate-limit {
  responses-per-second 10;
  nxdomains-per-second 0;
  max-table-size 40000;
};

25-Oct-2012 21:34:32.850 rate-limit: limit responses to a.b.c.0/24 for
ripe.net IN ANY  (0002000e)
25-Oct-2012 21:34:35.059 rate-limit: stop limiting responses to
a.b.c.0/24 for ripe.net IN ANY  (0002000e)
25-Oct-2012 21:34:42.721 rate-limit: limit responses to a.b.c.0/24 for
ripe.net IN ANY  (0002000e)
25-Oct-2012 21:34:44.900 rate-limit: stop limiting responses to
a.b.c.0/24 for ripe.net IN ANY  (0002000e)

It looks like rate-limits kick in for this network, but two or three
seconds later the rate-limit is removed. There are many such log lines,
showing the limit being removed around two seconds after it is first
applied. I thought the limit would be enforced for at least "window"
seconds. Have I misunderstood something?

Regards,

Anand