Here i using the code for increment MAC address of last bit after increment last bit overflow so to over come again recount from starting eg: last position is FF then after we increment by 1 we start count by 00 ----------------

#!/bin/sh
mac=$(ifconfig eth0|grep HWaddr|awk '{print $5}'| tr '[a-z]' '[A-Z]' |
+ cut -d ':' -f1-5)
maclast=$(ifconfig eth0|grep HWaddr|awk '{print $5}'| tr '[a-z]' '[A-Z
+]' | cut -d ':' -f6)
echo "Mac address= $mac:$maclast"
decmac=$(echo "ibase=16; $maclast"|bc)
if [ $decmac -eq '241' ]
then
macinc='00'
else
incout=`expr $decmac + 1 `
macinc=$(echo "obase=16; $incout"|bc)
fi
echo "Mac address= $mac:$macinc"
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OUTPUT:

Mac address= 00:19:D1:F6:F7:F1

Mac address= 00:19:D1:F6:F7:00
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