DNS records serial number

Solution 1:

No. You must change the serial number every time you make a change, and it must be a higher number than the previous one. This ensures proper propagation and loading for slave zones.

I recommend using a ten-digit serial, using the date (in YYYYMMDD format). Today would be 2011123000. Next revision today would be 2011123001. This allows for 99 revisions. The serial number will increment naturally using this method.

Solution 2:

If you don't change the serial number, by the next zone transfer, the changes you've made will not be recognized (as the entire zone will be recognized as unchanged), and thus you might end up getting the updated records overwritten.

But it's only important if you want to maintain the changes you've made, if you just made them for fun, I'd say it's not important :-)