From ISC Dhcp user

[Simon Hobson]

Vladislav A Kulikov wrote:

>class "blah-blah-blah" {
>   match if (binary-to-ascii(16,8,":",substring(option 
>agent.remote-id,2,6))="xx:xx:xx:xx:xx:xx" and 
>binary-to-ascii(10,8,"",suffix(
>option agent.circuit-id,1))="AA");
>}
>pool {
>   range 10.10.10.1;
>   allow members of "blah-blah-blah";
>}
>
>The client connects the first computer - gets the coveted IP 
>address, as if all is well.
>But as soon as the client needs to connect the cable to another 
>computer - there is a problem: hardware ethernet and uid does not 
>correspond to the lease granted to the IP address 10.10.10.1

No, your client won't match the class on a renewal because option 
agent.circuit-id won't be set - the renewal packet will be unicast 
and so not handles by the relay agent. Check your 
switch/router/whatever is setting that option to see if it has a 
snoop facility where it will set it even on unicast packets.

-- 
Simon Hobson

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