diff --git a/Netdisco/Changes b/Netdisco/Changes
index 18fa7bf8..03a6a517 100644
--- a/Netdisco/Changes
+++ b/Netdisco/Changes
@@ -4,6 +4,7 @@
 
   * Display port descriptions in topology editing form
   * Support store_modules config (default true)
+  * Support for discover_min_age
 
 2.013001 - 2013-08-23
 
diff --git a/Netdisco/Makefile.PL b/Netdisco/Makefile.PL
index e38097da..3e84d52e 100644
--- a/Netdisco/Makefile.PL
+++ b/Netdisco/Makefile.PL
@@ -23,6 +23,7 @@ requires 'List::MoreUtils' => 0.33;
 requires 'MIME::Base64' => 3.13;
 requires 'Moo' => 1.001000;
 requires 'MCE' => 1.408;
+requires 'Net::Domain' => 1.23;
 requires 'Net::DNS' => 0.72;
 requires 'Net::MAC' => 2.103622;
 requires 'NetAddr::IP' => 4.068;
diff --git a/Netdisco/lib/App/Netdisco/DB/Result/Device.pm b/Netdisco/lib/App/Netdisco/DB/Result/Device.pm
index 1ae4b7b0..1d83f3d8 100644
--- a/Netdisco/lib/App/Netdisco/DB/Result/Device.pm
+++ b/Netdisco/lib/App/Netdisco/DB/Result/Device.pm
@@ -250,4 +250,28 @@ between the date stamp and time stamp. That is:
 
 sub last_arpnip_stamp  { return (shift)->get_column('last_arpnip_stamp')  }
 
+=head2 since_last_discover
+
+Number of seconds which have elapsed since the value of C<last_discover>.
+
+=cut
+
+sub since_last_discover  { return (shift)->get_column('since_last_discover')  }
+
+=head2 since_last_macsuck
+
+Number of seconds which have elapsed since the value of C<last_macsuck>.
+
+=cut
+
+sub since_last_macsuck  { return (shift)->get_column('since_last_macsuck')  }
+
+=head2 since_last_arpnip
+
+Number of seconds which have elapsed since the value of C<last_arpnip>.
+
+=cut
+
+sub since_last_arpnip  { return (shift)->get_column('since_last_arpnip')  }
+
 1;
diff --git a/Netdisco/lib/App/Netdisco/DB/ResultSet/Device.pm b/Netdisco/lib/App/Netdisco/DB/ResultSet/Device.pm
index 2f8066e3..7be1cc07 100644
--- a/Netdisco/lib/App/Netdisco/DB/ResultSet/Device.pm
+++ b/Netdisco/lib/App/Netdisco/DB/ResultSet/Device.pm
@@ -37,8 +37,11 @@ sub with_times {
           uptime_age => \("replace(age(timestamp 'epoch' + uptime / 100 * interval '1 second', "
             ."timestamp '1970-01-01 00:00:00-00')::text, 'mon', 'month')"),
           last_discover_stamp => \"to_char(last_discover, 'YYYY-MM-DD HH24:MI')",
-          last_macsuck_stamp => \"to_char(last_macsuck,  'YYYY-MM-DD HH24:MI')",
-          last_arpnip_stamp => \"to_char(last_arpnip,   'YYYY-MM-DD HH24:MI')",
+          last_macsuck_stamp  => \"to_char(last_macsuck,  'YYYY-MM-DD HH24:MI')",
+          last_arpnip_stamp   => \"to_char(last_arpnip,   'YYYY-MM-DD HH24:MI')",
+          since_last_discover => \"extract(epoch from (age(now(), last_discover)))",
+          since_last_macsuck  => \"extract(epoch from (age(now(), last_macsuck)))",
+          since_last_arpnip   => \"extract(epoch from (age(now(), last_arpnip)))",
         },
       });
 }
diff --git a/Netdisco/lib/App/Netdisco/Daemon/Worker/Manager.pm b/Netdisco/lib/App/Netdisco/Daemon/Worker/Manager.pm
index 139611b9..047196f2 100644
--- a/Netdisco/lib/App/Netdisco/Daemon/Worker/Manager.pm
+++ b/Netdisco/lib/App/Netdisco/Daemon/Worker/Manager.pm
@@ -3,7 +3,6 @@ package App::Netdisco::Daemon::Worker::Manager;
 use Dancer qw/:moose :syntax :script/;
 use Dancer::Plugin::DBIC 'schema';
 
-use App::Netdisco::Util::Device 'is_discoverable';
 use Net::Domain 'hostfqdn';
 use Try::Tiny;
 
@@ -57,10 +56,6 @@ sub worker_body {
       while (my $job = $rs->next) {
           my $jid = $job->job;
 
-          # filter for discover_*
-          next unless is_discoverable($job->device);
-          debug sprintf "mgr (%s): job %s is discoverable", $wid, $jid;
-
           # check for available local capacity
           next unless $self->do('capacity_for', $job->action);
           debug sprintf "mgr (%s): processing node has capacity for job %s (%s)",
diff --git a/Netdisco/lib/App/Netdisco/Daemon/Worker/Poller/Device.pm b/Netdisco/lib/App/Netdisco/Daemon/Worker/Poller/Device.pm
index bfd96ee3..999b24d4 100644
--- a/Netdisco/lib/App/Netdisco/Daemon/Worker/Poller/Device.pm
+++ b/Netdisco/lib/App/Netdisco/Daemon/Worker/Poller/Device.pm
@@ -4,7 +4,7 @@ use Dancer qw/:moose :syntax :script/;
 use Dancer::Plugin::DBIC 'schema';
 
 use App::Netdisco::Util::SNMP 'snmp_connect';
-use App::Netdisco::Util::Device 'get_device';
+use App::Netdisco::Util::Device qw/get_device is_discoverable/;
 use App::Netdisco::Core::Discover ':all';
 use App::Netdisco::Daemon::Util ':all';
 
@@ -59,7 +59,11 @@ sub discover {
 
   if ($device->in_storage
       and $device->vendor and $device->vendor eq 'netdisco') {
-      return job_done("Skipped discover for pseudo-device $host");
+      return job_done("discover skipped: $host is pseudo-device");
+  }
+
+  unless (is_discoverable($device->ip)) {
+      return job_defer("discover deferred: $host is not discoverable");
   }
 
   my $snmp = snmp_connect($device);
diff --git a/Netdisco/lib/App/Netdisco/Manual/Configuration.pod b/Netdisco/lib/App/Netdisco/Manual/Configuration.pod
index 58a52b56..9b0b1c61 100644
--- a/Netdisco/lib/App/Netdisco/Manual/Configuration.pod
+++ b/Netdisco/lib/App/Netdisco/Manual/Configuration.pod
@@ -305,6 +305,13 @@ but don't talk SNMP. For example:
    - 'cisco\s+AIR-LAP'
    - '(?i)Cisco\s+IP\s+Phone'
 
+=head3 C<discover_min_age>
+
+Value: Number. Default: 0.
+
+Sets the minimum amount of time in seconds which must elapse between any two
+discover jobs for a device.
+
 =head3 C<macsuck_all_vlans>
 
 Value: Boolean. Default: C<false>.
@@ -590,10 +597,6 @@ C<col_xxx_show>
 
 =item *
 
-C<discover_min_age>
-
-=item *
-
 C<expire_devices>
 
 =item *
diff --git a/Netdisco/lib/App/Netdisco/Util/Device.pm b/Netdisco/lib/App/Netdisco/Util/Device.pm
index cc30d221..52b3630b 100644
--- a/Netdisco/lib/App/Netdisco/Util/Device.pm
+++ b/Netdisco/lib/App/Netdisco/Util/Device.pm
@@ -52,7 +52,7 @@ sub get_device {
     ->search({alias => $ip})->first;
   $ip = $alias->ip if defined $alias;
 
-  return schema('netdisco')->resultset('Device')
+  return schema('netdisco')->resultset('Device')->with_times
     ->find_or_new({ip => $ip});
 }
 
@@ -71,13 +71,15 @@ Returns false if the host is not permitted to discover the target device.
 
 =cut
 
+sub _bail_msg { debug $_[0]; return 0; }
+
 sub is_discoverable {
   my ($ip, $remote_type) = @_;
   my $device = get_device($ip) or return 0;
 
   if ($remote_type) {
-      return 0 if
-        scalar grep {$remote_type =~ m/$_/}
+      return _bail_msg("is_discoverable: device matched discover_no_type")
+        if scalar grep {$remote_type =~ m/$_/}
                     @{setting('discover_no_type') || []};
   }
 
@@ -88,7 +90,8 @@ sub is_discoverable {
   if (scalar @$discover_no) {
       foreach my $item (@$discover_no) {
           my $ip = NetAddr::IP::Lite->new($item) or return 0;
-          return 0 if $ip->contains($addr);
+          return _bail_msg("is_discoverable: device matched discover_no")
+            if $ip->contains($addr);
       }
   }
 
@@ -98,7 +101,16 @@ sub is_discoverable {
           my $ip = NetAddr::IP::Lite->new($item) or return 0;
           ++$okay if $ip->contains($addr);
       }
-      return 0 if not $okay;
+      return _bail_msg("is_discoverable: device failed to match discover_only")
+        if not $okay;
+  }
+
+  my $discover_since = setting('discover_min_age') || 0;
+
+  if ($device->since_last_discover
+      and $device->since_last_discover < $discover_since) {
+
+      return _bail_msg("is_discoverable: last discovered less than discover_min_age");
   }
 
   return 1;