diff --git a/perl-xCAT/xCAT/Schema.pm b/perl-xCAT/xCAT/Schema.pm
index c8e65468b..475bd97c8 100644
--- a/perl-xCAT/xCAT/Schema.pm
+++ b/perl-xCAT/xCAT/Schema.pm
@@ -538,6 +538,7 @@ site => {
    "  domain:\tThe DNS domain name used for the cluster.\n\n".
    "  forwarders:\tThe DNS servers at your site that can provide names outside of the cluster.  The DNS on the management node will forward requests it does not know to these servers.\n\n".
    "  fsptimeout:\tThe timeout, in milliseconds, to use when communicating with  FSPs.\n\n".
+   "  genmacprefix:\tWhen generating mac addresses automatically, use this manufacturing prefix (i.e. 00:11:aa)\n\n".
    "  genpasswords:\tAutomatically generate random passwords for BMCs when configuring them.\n\n".
    "  installdir:\tThe local directory name used to hold the node deployment packages.\n\n".
    "  installloc:\tThe location that service nodes should mount the install directory from in format hostname:/path.  If hostname is omitted, it defaults to the management node.\n\n".
diff --git a/perl-xCAT/xCAT/VMCommon.pm b/perl-xCAT/xCAT/VMCommon.pm
index 14907f2d7..b935e4e1d 100644
--- a/perl-xCAT/xCAT/VMCommon.pm
+++ b/perl-xCAT/xCAT/VMCommon.pm
@@ -1,4 +1,5 @@
 package xCAT::VMCommon;
+use Socket;
 use strict;
 #Functions common to virtualization management (KVM, Xen, VMware)
 sub grab_table_data{ #grab table data relevent to VM guest nodes
@@ -8,6 +9,8 @@ sub grab_table_data{ #grab table data relevent to VM guest nodes
   my $vmtab = xCAT::Table->new("vm");
   my $hmtab = xCAT::Table->new("nodehm");
   my $nttab = xCAT::Table->new("nodetype");
+  my $sitetab = xCAT::Table->new("site");
+  $cfghash->{site}->{genmacprefix} = xCAT::Utils->get_site_attribute('genmacprefix');
   if ($hmtab) {
       $cfghash->{nodehm}  = $hmtab->getNodesAttribs($noderange,['serialspeed']);
   }
@@ -33,4 +36,79 @@ sub grab_table_data{ #grab table data relevent to VM guest nodes
   }
 }
 
+sub getMacAddresses {
+    my $tablecfg = shift;
+    my $node = shift;
+    my $count = shift;
+    my $mactab = xCAT::Table->new("mac",-create=>1);
+    my $macdata = $tablecfg->{mac}->{$node}->[0]->{mac};
+    unless ($macdata) { $macdata ="" }
+    my @macs;
+    my $macaddr;
+    foreach $macaddr (split /\|/,$macdata) {
+         $macaddr =~ s/\!.*//;
+         push @macs,lc($macaddr);
+    }
+    $count-=scalar(@macs);
+    my $updatesneeded=0;
+    if ($count > 0) {
+        $updatesneeded = 1;
+    }
+
+    while ($count > 0) { #still need more, autogen
+        $macaddr = "";
+        while (not $macaddr) {
+            $macaddr = lc(genMac($node,$tablecfg->{site}->{genmacprefix}));
+            if ($tablecfg->{usedmacs}->{$macaddr}) {
+                $macaddr = "";
+            }
+        }
+        $count--;
+        $tablecfg->{usedmacs}->{$macaddr} = 1;
+        if (not $macdata) {
+            $macdata = $macaddr;
+        } else {
+            $macdata .= "|".$macaddr;
+        }
+        push @macs,$macaddr;
+    }
+    if ($updatesneeded) {
+        my $mactab = xCAT::Table->new('mac',-create=>1);
+        $mactab->setNodeAttribs($node,{mac=>$macdata});
+        $tablecfg->{dhcpneeded}->{$node}=1; #at our leisure, this dhcp binding should be updated
+    }
+    return @macs;
+#    $cfghash->{usedmacs}-{lc{$mac}};
+
+}
+
+sub genMac { #Generates a mac address for a node, does NOT assure uniqueness, calling code needs to do that
+    my $node=shift;
+    my $prefix = shift;
+    if ($prefix) { #Specific prefix requested, honor it
+        my $tail = int(rand(0xffffff)); #With only 24 bits of space, use random bits;
+        $tail = sprintf("%06x",$tail);
+        $tail =~ s/(..)(..)(..)/:$1:$2:$3/;
+        return $prefix.$tail;
+    }
+    my $allbutmult = 0xfeff; # to & with a number to ensure multicast bit is *not* set
+    my $locallyadministered = 0x200; # to | with the 16 MSBs to indicate a local mac
+    my $leading = int(rand(0xffff));
+    $leading = $leading & $allbutmult;
+    $leading = $leading | $locallyadministered;
+    #If this nodename is a resolvable name, we'll use that for the other 32 bits
+    my $low32;
+    my $n;
+    if ($n = inet_aton($node)) {
+        $low32= unpack("N",$n);
+    }
+    unless ($low32) { #If that failed, just do 32 psuedo-random bits
+        $low32 = int(rand(0xffffffff));
+    }
+    my $mac;
+    $mac = sprintf("%04x%08x",$leading,$low32);
+    $mac =~s/(..)(..)(..)(..)(..)(..)/$1:$2:$3:$4:$5:$6/;
+    return $mac;
+
+}
 1;
diff --git a/xCAT-server/lib/xcat/plugins/esx.pm b/xCAT-server/lib/xcat/plugins/esx.pm
index 94156654d..305e1f648 100644
--- a/xCAT-server/lib/xcat/plugins/esx.pm
+++ b/xCAT-server/lib/xcat/plugins/esx.pm
@@ -64,73 +64,6 @@ sub handled_commands{
 	};
 }
 
-#CANDIDATE FOR COMMON CODE
-sub getMacAddresses {
-    my $node = shift;
-    my $count = shift;
-    my $macdata = $tablecfg{mac}->{$node}->[0]->{mac};
-    unless ($macdata) { $macdata ="" }
-    my @macs;
-    my $macaddr;
-    foreach $macaddr (split /\|/,$macdata) {
-         $macaddr =~ s/\!.*//;
-         push @macs,lc($macaddr);
-    }
-    $count-=scalar(@macs);
-    my $updatesneeded=0;
-    if ($count > 0) {
-        $updatesneeded = 1;
-    }
-
-    while ($count > 0) { #still need more, autogen
-        $macaddr = "";
-        while (not $macaddr) {
-            $macaddr = lc(genMac($node));
-            if ($tablecfg{usedmacs}->{$macaddr}) {
-                $macaddr = "";
-            }
-        }
-        $count--;
-        $tablecfg{usedmacs}->{$macaddr} = 1;
-        if (not $macdata) {
-            $macdata = $macaddr;
-        } else {
-            $macdata .= "|".$macaddr;
-        }
-        push @macs,$macaddr;
-    }
-    if ($updatesneeded) {
-        my $mactab = xCAT::Table->new('mac',-create=>1);
-        $mactab->setNodeAttribs($node,{mac=>$macdata});
-        $tablecfg{dhcpneeded}->{$node}=1; #at our leisure, this dhcp binding should be updated
-    }
-    return @macs;
-#    $cfghash->{usedmacs}-{lc{$mac}};
-
-}
-
-sub genMac { #Generates a mac address for a node
-    my $node=shift;
-    my $allbutmult = 0xfeff; # to & with a number to ensure multicast bit is *not* set
-    my $locallyadministered = 0x200; # to | with the 16 MSBs to indicate a local mac
-    my $leading = int(rand(0xffff));
-    $leading = $leading & $allbutmult;
-    $leading = $leading | $locallyadministered;
-    #If this nodename is a resolvable name, we'll use that for the other 32 bits
-    my $low32;
-    my $n;
-    if ($n = inet_aton($node)) {
-        $low32= unpack("N",$n);
-    }
-    unless ($low32) { #If that failed, just do 32 psuedo-random bits
-        $low32 = int(rand(0xffffffff));
-    }
-    my $mac;
-    $mac = sprintf("%04x%08x",$leading,$low32);
-    $mac =~s/(..)(..)(..)(..)(..)(..)/$1:$2:$3:$4:$5:$6/;
-    return $mac;
-
-}
 
 
 
@@ -1224,7 +1157,7 @@ sub create_nic_devs {
     my @networks = split /,/,$tablecfg{vm}->{$node}->[0]->{nics};
     my @devs;
     my $idx = 0;
-    my @macs = getMacAddresses($node,scalar @networks);
+    my @macs = xCAT::VMCommon::getMacAddresses(\%tablecfg,$node,scalar @networks);
     my $connprefs=VirtualDeviceConnectInfo->new(
                             allowGuestControl=>1,
                             connected=>0,