[Pdns-users] TCP Query Problem

[InterNetworX | Hostmaster]

Hello,

we're running PowerDNS since a long time. Usaly TCP queries are working,
only from time to time we need to restart PowerDNS if it stops.

But today, we did not changed anything, no more TCP queries are
possible. If we restart, only one query is possible, then it stops working.

$ /etc/init.d/pdns restart
Restarting PowerDNS authoritative nameserver: stopping and waiting..done
Starting PowerDNS authoritative nameserver: started

$ dig NS domain.fr @ns.abc.de +short +tcp
ns.abc.de.
ns2.abc.de.
ns3.abc.de.

$ dig NS domain.fr @ns.abc.de +short +tcp

; <<>> DiG 9.4.3-P1 <<>> NS domain.fr @ns.abc.de +short +tcp
;; global options:  printcmd
;; connection timed out; no servers could be reached

$ pdns_server --version
Version: 2.9.22, compiled on Mar 10 2009, 12:13:17 with gcc version 4.3.2

In pdns.conf we hade the configuration:

disable-tcp=no

Now I tried to set:

max-tcp-connections=300

But nothing changed.

The stats shows:

tcp-answers	1	Number of answers sent out over TCP
tcp-queries	1	Number of TCP queries received

I already found some other people with the same problem but no solution.
Any idea?

Thanks

Mario