HowTo handle DHCP Log reverse IP addresses

[tyralla]

Hi,

I'm looking for a possibility to join DHCP events together with transaction command. Join fields are IP and MAC address.

Unfortunately DHCP Log contains in some cases the IP in reverse.
As an example:

TIMESTAMP,DNS Update Request,66.1.168.192,MachinName,,

Correct IP in this case would be 192.168.1.66.

Is there any way to reverse the IP to allow matching with the rest of the IP entries in this field?

Thanks!

[Ayn · Accepted solution]

Yeah I've seen that too, Microsoft's DHCP server seems to have a weird behaviour with that.

If you have the original IP in a field, let's call it ip, you could reorder the octets with a rex statement.

... | rex mode=sed field=ip "s/(\d+)\.(\d+)\.(\d+)\.(\d+)/\4.\3.\2.\1/"

[tyralla]

Works perfect - Thanks!