Searching dhcp.leases for an IP (by MAC)

Nicholas Leippe nick at leippe.com
Tue Dec 12 09:33:00 MST 2006


On Tuesday 12 December 2006 09:20, Chris Carey wrote:
> I need to write a function to search dhcpd.leases file to find IP
> addresses (I have the corresponding MAC address). This would be easy
> for me if the file had each lease on one line. In that case I could
> just grep for the MAC address , then parse out the IP address.
> However, the IP address is 5 lines above the said MAC address:
>
> lease 10.10.32.209 {
>   starts 1 2006/12/11 19:04:32;
>   ends 2 2006/12/12 19:04:32;
>   binding state active;
>   next binding state free;
>   hardware ethernet 00:02:a1:1a:9c:94;
>   uid "\001\000\002\241\032\234\221";
> }

grep -B 5
eg:

grep -B 5 <mac addr> |
grep '\(lease\|hardware.*ethernet\)'

or use awk ;)






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