How does DHCPD determine what IP address to assign and...

[Ryan McCain]

>>> On Fri, Dec 28, 2007 at 11:30 AM, in message
<4774DE52.5D1A.003A.0 at dss.state.la.us>, "Ryan McCain"
<Ryan.McCain at dss.state.la.us> wrote: 
>>>> On Fri, Dec 28, 2007 at 10:32 AM, in message
> <B2ED9364017FF54FB9392221F9A49845025DEA35 at nwpsrv08.edj.ad.edwardjones.com>,
> "Stulic,Damjan" <damjan.stulic at edwardjones.com> wrote: 
>> You could test the validity of your config file with
>> /usr/sbin/dhcpd -q -t -cf <config file>
>> 
>> Damjan Stulic
>> IS Security Identity Management
>> Edward Jones
>> 
> 
> That command is very useful.  Although for me I had to omit the -q for it to 
> work.
> 
> After trial and error I got the config file to pass using this syntax:
> 
> class "DialUp" {
>     match if (substring(suffix(dhcp-client-identifier,7),0,5)="Async")
>      or
>      (substring(suffix(dhcp-client-identifier,6),0,5)="Async") ;
>        log (info, " Matched Dialup Rule");
> }
> 
> -SNIP-
> 
> subnet 10.116.6.0 netmask 255.255.255.0 {
>      pool {
>          allow members of "DialUp";
>          range 10.116.6.1 10.116.6.8;
>          option routers 10.116.6.1;
>          }
> }
> 
> -SNIP-
> 
> #DSS - Cisco VPN
> subnet 10.116.6.0 netmask 255.255.255.0 {
>   range 10.116.6.9 10.116.6.179 ;
>   option routers 10.116.6.254;
> }
> 
> -SNIP-
> 
> ......The next test will be to see if it actually works.
> 
> 
> Thanks,
> Ryan


I had someone dial in to test the setup and it didn't allocate an IP address in the 'DialUp' class as I had hoped.  Here is my dhcpd.conf:

-SNIP-

class "DialUp" {
    match if (substring(suffix(dhcp-client-identifier,7),0,5)="Async")
     or
     (substring(suffix(dhcp-client-identifier,6),0,5)="Async") ;
       log (info, " Matched Dialup Rule");
}

-SNIP_

subnet 10.116.6.0 netmask 255.255.255.0 {
     pool {
         allow members of "DialUp";
         range 10.116.6.1 10.116.6.8;
         option routers 10.116.6.1;
         }
}

-SNIP-

#DSS - Cisco VPN
subnet 10.116.6.0 netmask 255.255.255.0 {
  range 10.116.6.9 10.116.6.179 ;
  option routers 10.116.6.254;
}


.../var/log/messages shows this:

Dec 28 13:35:54 dss-cs99la59 dhcpd: DHCPOFFER on 10.116.6.179 to 00:10:7b:4d:73:c6 via 10.116.6.251
Dec 28 13:35:54 dss-cs99la59 dhcpd: DHCPREQUEST for 10.116.6.179 (10.120.11.85) from 00:10:7b:4d:73:c6 via 10.116.6.251

..And the leases file showed this entry:

  lease 10.116.6.179 {
  starts 5 2007/12/28 19:35:54;
  ends 6 2007/12/29 19:35:54;
  binding state active;
  next binding state free;
  hardware ethernet 00:10:7b:4d:73:c6;
  uid "\000cisco-10.116.6.251-Async43";

..As you can see it handed out an IP address in the second subnet I posted above. The goal is to have any DHCP client that connects from the 10.116.6.0 network with "Async" in the UID be assigned an IP address between 10.116.6.1 - 10.116.6.8 while any other client connecting from the 10.116.6.0 network would be assigned an IP address between 10.116.6.9 - 10.116.6.179.

I've read through the man pages you guys recommended and I'm stumped. 

Thanks again,
Ryan