Hostname differences between servers

[Eugene Grosbein]

03.10.2018 2:13, Norman Elton wrote:

> An update after further research!
> 
> In the previous example, e8802ea2eb7f (an Apple device) is requesting
> 10.45.13.196. One server, landlord02, is erroneously stating that the
> client hostname is android-9375f90cad51e32f. It turns out that, a few
> days ago, landlord02 offered this IP address to an Android device with
> the hostname of android-9375f90cad51e32f. Looking at the source code,
> it appears that dhcpd is not reporting the hostname found in the
> packet, but rather, the information collected from its lease file.
> 
> I suspect this is a corner case, related to the failover mechanism.
> But is there a reason it's logging from the lease file and not from
> the packet itself? The log message could reasonably be interpreted to
> mean that e8802ea2eb7f is reporting an Android hostname.

And it did report that hostname. You should not have different hosts having same
MAC address in the network, and dhcpd cannot differentiate them anyway,
so it uses same lease.

If you have DHCP servers separated from users vlans by routers and DHCP relays
and your users differ not only by MAC but may have same MACs within differed vlans
identified by option 82, for example, than you need DHCP server other than ISC DHCPD.
FreeRADIUS with its DHCP module serves me just fine in such setup.