6 Replies Latest reply: Jul 10, 2013 4:30 PM by quarfie
quarfie Level 1 Level 1 (0 points)

I lost power to my server last night in a power outage.


Today the DNS Server doesn't seem to be working. I verified that my server's IP is the primary name server on the clients, however all lookups are going to the secondary (public) name server and therefore giving the public IP address for LAN services.


To test it, I typed in Terminal (both on a client machine and on the server itself) "nslookup [myinternaldomain.com] [mydnsserverip]" and get ";; connection timed out; no servers could be reached"


When I load up Server Admin, I see that the DNS service is running but for Start Time it says "Not Available".


Tried stopping and starting the service.

iMac, Mac OS X (10.6.8)
  • MrHoffman Level 6 Level 6 (13,005 points)

    Are there any errors logged for the DNS server?  (Check the DNS server logs for diagnostics and details related to the server.  I've seen cases where the server is listed as running in Server Admin.app or in Server.app, but it really wasn't running, or wasn't running correctly.)


    As for the terminal, you can specify the IP address of the target DNS server with the dig command at the Terminal.app prompt:


    dig @ www.apple.com


    That dig command asks Google DNS (the server at IP address for an IP address of the Apple web servers.  Substitute your local IP address and your local host names for translation, and see what you get.


    I would not recommend the "secondary" be a public DNS server, as which DNS server gets selected for a DNS query is not particularly deterministic.  I much prefer to have "peer" servers specified; primary and secondary DNS servers that have the local address(es) and local DNS domain names, and to avoid referencing off-LAN DNS servers save via the root server and related queries generated from these local DNS servers.

  • quarfie Level 1 Level 1 (0 points)

    using dig I get the exact same result as nslookup.


    When I click the "log" tab in the DNS service in Server Admin, the only entry is "logfile turned over" (with today's date). I've had this issue for a long time, even though I have the "Log Level" set to "Debug" (which should give the most detailed logging right?).


    Thanks for suggestion re: using only local DNS servers on the LAN. I definitely have been meaning to bring in an expert to audit my DNS setup!

  • MrHoffman Level 6 Level 6 (13,005 points)

    To confirm, you're using the @ notation on the dig, and you've specified the IP address of your DNS server, correct?


    You can see if the DNS server (named) is really running with the following Terminal.app command:


    sudo lsof -i -P | grep -i ":53"


    That'll report anything on TCP and UDP port 53 (which is used by DNS) (plus possibly a few ports beginning with 53 that you can ignore).  If things are working, you should see some named processes.


    In general, you'll want to post the specific command used, and the full text of the response, as a starting point.  While it is distinctly possible there's an IP networking or cabling or DNS error here, there's not enough information posted to hint at a direction.  (It would definitely appear that the DNS server is not running, though.)


    Here's some DNS server configuration reading for you.  That sequence is for Snow Leopard 10.6, but will work the same with OS X Server on Lion 10.7 and Mountain Lion 10.8, if you've selected Show All Records within Server.app.

  • quarfie Level 1 Level 1 (0 points)

    Thanks for that link. It looks about at my level so I'll have a read tonight. I am on 10.6.8


    Here's what I got back from the command you suggested (looks like all of these are just ports starting with "53" - confirming that DNS is not running?)


    mDNSRespo    36 _mdnsresponder    8u  IPv4 0xffffff800fe25980      0t0    UDP *:5353

    mDNSRespo    36 _mdnsresponder    9u  IPv6 0xffffff800fe25840      0t0    UDP *:5353

    mDNSRespo    36 _mdnsresponder   50u  IPv4 0xffffff8012030c00      0t0    UDP *:53697

    mDNSRespo    36 _mdnsresponder   51u  IPv6 0xffffff8012030340      0t0    UDP *:53697

    Python       50        _jabber    4u  IPv4 0xffffff8012cc4da8      0t0    TCP localhost:49277->localhost:5347 (ESTABLISHED)

    Python       75        _jabber    3u  IPv4 0xffffff8010120a08      0t0    TCP localhost:49177->localhost:5347 (ESTABLISHED)

    resolver    406        _jabber    4u  IPv4 0xffffff8012970418      0t0    TCP localhost:49172->localhost:5347 (ESTABLISHED)

    sm          407        _jabber    5u  IPv4 0xffffff80129727b8      0t0    TCP localhost:49170->localhost:5347 (ESTABLISHED)

    router      408        _jabber    4u  IPv4 0xffffff80127621c8      0t0    TCP localhost:5347 (LISTEN)

    router      408        _jabber    5u  IPv4 0xffffff80127615e8      0t0    TCP localhost:5347->localhost:49166 (ESTABLISHED)

    router      408        _jabber    6u  IPv4 0xffffff8012760a08      0t0    TCP localhost:5347->localhost:49167 (ESTABLISHED)

    router      408        _jabber    7u  IPv4 0xffffff80127627b8      0t0    TCP localhost:5347->localhost:49168 (ESTABLISHED)

    router      408        _jabber    8u  IPv4 0xffffff80129721c8      0t0    TCP localhost:5347->localhost:49170 (ESTABLISHED)

    router      408        _jabber    9u  IPv4 0xffffff8012abfda8      0t0    TCP localhost:5347->localhost:49172 (ESTABLISHED)

    router      408        _jabber   10u  IPv4 0xffffff8012abe5e8      0t0    TCP localhost:5347->localhost:49177 (ESTABLISHED)

    router      408        _jabber   11u  IPv4 0xffffff8012cc47b8      0t0    TCP localhost:5347->localhost:49277 (ESTABLISHED)

    c2s         409        _jabber    4u  IPv4 0xffffff8012760ff8      0t0    TCP localhost:49167->localhost:5347 (ESTABLISHED)

    mu-confer   410        _jabber    6u  IPv4 0xffffff8011d14a08      0t0    TCP localhost:49168->localhost:5347 (ESTABLISHED)

    s2s         411        _jabber    4u  IPv4 0xffffff8012761bd8      0t0    TCP localhost:49166->localhost:5347 (ESTABLISHED)

  • MrHoffman Level 6 Level 6 (13,005 points)

    Yeah; your DNS server isn't running.  You'd see some "named" processes if it was.


    In OS X Server 10.6.8 in Server Admin.app (unlike in various newer versions ), you can crank up the DNS debugging level through the GUI.  Do that.  Launch Server Admin.app, select the server, select DNS, select settings, and set the DNS log level settings to "debug", and see if you can get something more logged.


    The default DNS log file can be found and displayed via Console.app (Applications > Utilities) or from Terminal.app via the /Library/Logs/named.log file. 


    You might also find some relevant errors in /var/log/system.log file, depending on why the DNS startup is cratering.


    Console.app can also show you a mass of messages, and you might also see where named is encountering error(s).  If it's the usual crash-restart schtick, you'll get the same block of restart message(s) logged in the Console.app messages every five or ten or fifteen seconds; whatever the restart interval for the DNS server.


    Though it's a little late here, I'd generally recommend configuring a less-interruptible power supply — a LIPS, as they're never truly uninterruptible — battery backup — as OS X Server doesn't really like having the power yanked out.

  • quarfie Level 1 Level 1 (0 points)

    I do have a "LIPS" (ha) but emphasis on the L this time it seems. I actually just realized that this problem started over a week ago when one machine stopped being able to connect to file sharing with the domain name. I guess all the others had the correct DNS cached until the blackout forced everyone to restart.


    I did set the log level to "Debug" in Server Admin, but I still don't get any entries in named.log. Other than "log file turned over". It seems the log file is archived every day and 5 days are kept. Every one simply has the one entry "log file turned over"


    However when I click "All messages" in Console, and type "named" in the filter by, I do see lots of relevent data, and this happens every 10 seconds!


    13-07-10 7:11:06 PMnamed[36027]starting BIND 9.6-ESV-R4-P3 -f
    13-07-10 7:11:06 PMnamed[36027]built with '--prefix=/usr' '--mandir=/usr/share/man' '--infodir=/usr/share/info' '--disable-dependency-tracking' '--sysconfdir=/private/etc' '--localstatedir=/private/var' '--enable-atomic=no' '--with-libxml2=/usr/include/libxml2' 'CFLAGS=-arch x86_64 -arch i386 -arch ppc -g -Os -pipe ' 'LDFLAGS=-arch x86_64 -arch i386 -arch ppc ' 'CXXFLAGS=-arch x86_64 -arch i386 -arch ppc -g -Os -pipe '
    13-07-10 7:11:06 PMnamed[36027]/etc/dns/publicView.conf.apple:1: undefined ACL '192.168.7.*'
    13-07-10 7:11:06 PMnamed[36027]loading configuration: failure
    13-07-10 7:11:06 PMnamed[36027]exiting (due to fatal error)
    13-07-10 7:11:06 PMcom.apple.launchd[1](org.isc.named[36027]) Exited with exit code: 1
    13-07-10 7:11:06 PMcom.apple.launchd[1](org.isc.named) Throttling respawn: Will start in 10 seconds


    So I removed 192.168.7.* from the "Accept recursive queries from the following networks" box in Server Admin, and now it seems everything works.


    I added that entry 4 months ago! I think I had added the entry while trying to get my remote office IP phones working with the name server, but it never solved the problem and the phones still refuse to use the name server.


    Anyway, my immediate problem is solved. thank you so much! I'll check out your reading materials tonight and see if I can figure out the less urgent phone issues!