RHEL BIND Server Intermittent error

Question

I have a RHEL 5.7 server running bind-9.3.6-16.P1.el5. At seemingly random points during the day, the DNS will fail to resolve hosts on the LAN for about ten seconds. WAN hosts always resolve. Then it goes back to working fine. I have logging enabled and there are no errors in the logs. Total devices using this DNS server are about 50; its not under heavy load. I have multiple views set up in the configuration.

I used the system-config-bind RHEL tool to configure this. My suspicion is that this tool added something to the configuration that "Refreshes" or "Performs maintenance" at some interval, or some configuration piece that doesn't and that is when the LAN hosts are unresolvable.

// Red Hat BIND Configuration Tool
// 
// Default initial "Caching Only" name server configuration
//


    logging {
    channel "custom" {
        syslog local0;
        severity dynamic;
        print-category yes;
        print-severity yes;
        print-time yes;
    };
    category lame-servers {
        custom;
    };
    category xfer-in {
        custom;
    };
    category xfer-out {
        custom;
    };
    category network {
        custom;
    };
    category dnssec {
        custom;
    };
    category database {
        custom;
    };
    category default {
        custom;
    };
    category dispatch {
        custom;
    };
    category general {
        custom;
    };
    category client {
        custom;
    };
    category notify {
        custom;
    };
    category resolver {
        custom;
    };
    category queries {
        custom;
    };
    category security {
        custom;
    };
    category config {
        custom;
    };
    category delegation-only {
        custom;
    };
    };
















    options {


    querylog yes;
    dnssec-enable yes;
    directory "/var/named";
    dump-file "/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";

    forwarders { 8.8.8.8; 8.8.4.4; }; // ISP primary/secondary


    /*
     * If there is a firewall between you and nameservers you want
     * to talk to, you might need to uncomment the query-source
     * directive below.  Previous versions of BIND always asked
     * questions using port 53, but BIND 8.1 uses an unprivileged
     * port by default.
     */
     // query-source address * port 53;
      };




    view "chill" {
    match-clients {
    192.168.3.0/24;
    };
    zone "2.168.192.IN-ADDR.ARPA." IN {
    type master;
    file "192.168.2.db";
    };
    zone "laptop." IN {
    type master;
    file "laptop_0.db";
    };

    zone "media." IN {
    type master;
    file "media_1.db";
    };
    zone     "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa." IN {
        type master;
    file "chill_named.ip6.local";
    allow-update { none; };
    };
    zone "255.in-addr.arpa." IN {
    type master;
    file "chill_named.broadcast";
    allow-update { none; };
    };
    zone "0.in-addr.arpa." IN {
    type master;
    file "chill_named.zero";
    allow-update { none; };
    };
    zone "localhost." IN {
    type master;
    file "chill_localhost.zone";
    allow-update { none; };
    };
    zone "." IN {
    type hint;
    file "chill_named.root";
    };

    match-destinations {
    any;
};
};
view "media" {
    match-clients {
    192.168.1.0/24;
};






    match-destinations {
    any;
};
    recursion yes;






zone "synbackup." IN {
    type master;
    file "synbackup.db";
};
zone "media." IN {
    type master;
    file "media_0.db";
};
zone "laptop." IN {
    type master;
    file "laptop.db";
};

zone "1.168.192.IN-ADDR.ARPA." IN {
    type master;
    file "192.168.1.db";
};

zone "." IN {
    type hint;
    file "named.root";
};

zone "localdomain." IN {
    type master;
    file "localdomain.zone";
    allow-update { none; };
};

zone "localhost." IN {
    type master;
    file "localhost.zone";
    allow-update { none; };
};

zone "0.0.127.in-addr.arpa." IN {
    type master;
    file "named.local";
    allow-update { none; };
};

zone "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa." IN {
        type master;
    file "named.ip6.local";
    allow-update { none; };
};

zone "255.in-addr.arpa." IN {
    type master;
    file "named.broadcast";
    allow-update { none; };
};

zone "0.in-addr.arpa." IN {
    type master;
    file "named.zero";
    allow-update { none; };
};




};

include "/etc/rndc.key";

Also no errors on the interface:

eth0      Link encap:Ethernet  HWaddr 00:xx:xx:xx:xx:xx  
          inet addr:192.168.1.xx  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::222:19ff:fe65:xxxx/xx Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2109561869 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3527205451 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:2120862115404 (1.9 TiB)  TX bytes:4168472739611 (3.7 TiB)
          Interrupt:185 Memory:ec000000-ec012800 

Answer 1

There's a RH KB article which says this happens when the cache expires, but still contains IPv6 information (they're pretty vague in the root cause).

They suggest disabling IPv6 support, if that's an option.

add OPTIONS="-4" to /etc/sysconfig/named