ASCII hardware address

[Martin Jackson]

Robin Breathe wrote:
> Hello,
> 
> I have problems obtaining a nice ASCII representation of the client
> hardware address within "on ..." clauses.
> Using the following syntax:
> 	binary-to-ascii(16, 16, ".", suffix(hardware,6))
> I get things like "d.38b.cde8" when I expect "000d.038b.cde8".
> Is there any way to get dhcp-eval to output the complete format without
> dropping leading zeros or must this be "cleaned up" in post processing?
> If there's a quicker way to fish out the full address, I'm all ears.
> 
> Regards,
> Robin
> 

This should be a FAQ...I remember asking it a while ago. :)  Here is 
what's running on my dhcpd server pair:

  set macaddr = concat (
          suffix (concat ("0", binary-to-ascii (16, 8, "", 
substring(hardware, 1, 1))),2),
          suffix (concat ("0", binary-to-ascii (16, 8, "", 
substring(hardware, 2, 1))),2),
          suffix (concat ("0", binary-to-ascii (16, 8, "", 
substring(hardware, 3, 1))),2),
          suffix (concat ("0", binary-to-ascii (16, 8, "", 
substring(hardware, 4, 1))),2),
          suffix (concat ("0", binary-to-ascii (16, 8, "", 
substring(hardware, 5, 1))),2),
          suffix (concat ("0", binary-to-ascii (16, 8, "", 
substring(hardware, 6, 1))),2)
         );

The result is guaranteed to be 12 digits. You can then do things with 
macaddr - I use it to construct ddns-hostnames for clients that don't 
supply them.

Thanks,
Marty