Re: help on assigning invalid IP addresses

--On 17 januari 2020 16:06:20 +0100 Leonardo Boselli <[email protected]> 
wrote:

> subnet with some server (fixed public IP addresses), workstation (same,
> assigned by dhcp), portable (dhcp dynamic), peripherals using only link
> local fe80:: IPv6 addresses.
> All was fine until arrived a couple of peripherals that get their IPv4
> address via dhcp and there is no way to avoid them to get it, even if you
> access then only via IPv6 .
> I have added in the imcluded file that assign always the same address to
> workstations based on mac addresses record as
>
> host XRX0000AABBCCDD {
>     hardware ethernet 00:00:aa:bb:cc:dd;
>     fixed-address 10.240.13.112;
>     option routers 10.240.13.1;
>     option subnet-mask 255.255.255.0;
>     }
>
> but the resut is that while addresse in the "real" subnet assigned to
> workstations works fine an are correctly assigned, peripherals insist on
> getting public addresses from the pool of portables, that is something i
> do not want.
> How can i assign completely invalid (or better, unrouted) IPv4 addresses ?
>
> --
> Leonardo Boselli
> DICEA
> tel +39 0552758808  +39 3488605348
>
>


Just to check, do you have a specification for the "invalid" subnet in some 
way in the dhcp server pointing in the same direction as the "good" subnet?

It was quite a long time since I messed with dhcp so I may be wrong but I 
think that is required for what you want.  Like setting an extra (invalid) 
address on the same interface and maybe a shared network wrapping with both 
of the networks in the dhcp config (no available addresses for the bad one 
except the one fixed to the device).

// Emil