If the problem described below hits you, and you are on linux, try making a tcpdump of your server, like this:
tcpdump -w dump-file -s 1600 udp and port 53 Stop this dump after a minute or so, and then run 'dnsgram', which is found on http://svn.powerdns.com/dnsgram.bz2 Bunzip2 this file, and run: ./dnsgram dump-file This will emit a lot of debugging, but most importantly, a file called 'failed'. This lists all queries your nameserver never answered in the dump. This is a powerful hint which records might be broken. To sort this 'failed' file for most failed queries, run: sort -n -k 3 < failed Good luck! On Mon, Apr 23, 2007 at 03:45:20PM +0200, bert hubert wrote: > While most users report good results with PowerDNS Authoritative Server > 2.9.21, there are some important things you need to watch out for. > > PowerDNS 2.9.20 and lower were very lenient with parsing malformed IP > addresses, which could not be translated into valid DNS packets. These would > be served as '255.255.255.255'. > > PowerDNS 2.9.21 is very strict, and drops the question (or more precisely, > the answer) once it finds it can't correctly parse the information from the > database. > > This leads to rapid retransmits from your client nameservers, possibly > overloading your database! > > So if your database is suddenly overloaded, verify that all your database > records are correct. > > A quick way of doing is is trying to AXFR all your zones, and see which ones > fail. > > For MySQL, a trick is to try: > > select * FROM records WHERE (type='A' AND INET_ATON(content) IS NULL); > > Possibly followed by: > > DELETE FROM records WHERE (type='A' AND INET_ATON(content) IS NULL); > > Depending on your mood of the day. > > Other interesting queries are: > > select * from records where content like ' %'; > > So keep this in mind if your servers are suddenly overloaded after upgrading > all of them to 2.9.21! > > -- > http://www.PowerDNS.com Open source, database driven DNS Software > http://netherlabs.nl Open and Closed source services > _______________________________________________ > Pdns-users mailing list > [email protected] > http://mailman.powerdns.com/mailman/listinfo/pdns-users > > > !DSPAM:462cb88d326244495314143! -- http://www.PowerDNS.com Open source, database driven DNS Software http://netherlabs.nl Open and Closed source services _______________________________________________ Pdns-users mailing list [email protected] http://mailman.powerdns.com/mailman/listinfo/pdns-users
