# dhcp class



## jpoveda (Oct 21, 2011)

Hello,

I'm trying to deny access to Blackberry devices into my wireles network. Blackberry devices identifying itselfs with a device name like "BLACKBERRY-XXX". As I could read, an aproach to do that could be done configuring my dhcp server with somethng like this:


```
class "nobb" {
  match if not (substring (option dhcp-client-identifier, 1, 5) = "BLACK");
}
class "bb" {
  match if substring (option dhcp-client-identifier, 1, 5) = "BLACK";
}

subnet 172.17.140.0 netmask 255.255.252.0 {
  pool {
    allow members of "bb";
    range 172.17.140.254 172.17.140.255;
  }
  pool {
#deny members of "bb";
    allow members of "nobb";
    range 172.17.141.0 172.17.143.254;
  }
}
```

Unfortunally this doesn't work. Anyone has worked with dhcpd classes to give me the right way?

Best Regards.


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