Prevent PCs from using Server hostnames
Simon Hobson
dhcp1 at thehobsons.co.uk
Fri May 19 11:08:12 UTC 2017
"Zenz, Thomas" <Thomas.Zenz at oenb.at> wrote:
> To prevent Clients form using server hostnames and so pull traffic to the client, I added the following script:
No need.
IFF your servers are in the DNS (and not themselves allocated by the same DHCP) then DHCP is refuse to update the DNS with a matching entry.
If you look in your DNS zones, you'll find that the A records for your clients are also accompanied by a TXT record with some long "random" string. The TXT record is a key (hashed from client information) to show that the A record was created by the DHCP server - and if it's not present, then the DHCP server will not update/replace the A record.
This is there specifically to avoid the issue you describe - allowing a client to over-write DNS records that don't belong to DHCP clients.
It's not just servers - it's anything you've statically configured.
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