Hello,
i want to restrict access to a printer(HP color Laserjet2605dtn) to only a few computers.
The Printer has
IP:10.9.1.12
NM:255.255.255.240
(The printer has accepted both IP and Netmask, and is proudly showing them on the config webpage.)
This SHOULD restrict access to the range from 10.9.1.1 to 10.9.1.14, right?
But instead i still can Ping, telnet and http the printers address and print from IP-adresses throughout the subnet, e.g. from 10.9.1.200
Why this?
I am quite sure there is no redirection, or whatever.
Any ideas? Or do i have a major misunderstanding of netmasks?

Dirk

No. This is an IP misconfiguration that will cause the printer to send responses to addresses in the range 10.9.1.16-10.9.1.254 to the gateway, which will dutifully forward the packets to the right host. It may block communication with 10.9.1.17, as the printer will incorrectly consider that address a subnet broadcast address.

You cannot and should not use the wrong netmasks to block traffic. Put the printer in a separate subnet instead, and filter traffic on the router.