Heavy config file and vlan usage

Simon Hobson dhcp1 at thehobsons.co.uk
Tue Jun 19 18:07:18 UTC 2007

Emmanuel Lesouef wrote:

>  > Can you clarify what you want - I can see two interpretations and the
>>  answers are different (yes or no) depending on what you are trying to
>>  do !

>Currently, my DHCP update a DNS zone : testzone.intra
>There are several type of equipments ont the different vlans. For
>example, laptops, PCs and other computers are on vlan 3 whereas Avaya IP
>phones are on vlan 4.
>What I wanted to do, is to put IP phones on a DNS zone such as

OK, so the question is wrong !

Simple way to do this is to set ddns-domainname name to 
ipphones.testzone.intra in the appropriate subnet declaration. Each 
subnet can have it's own options, as can individual pools, or 
individual hosts - and not forgetting classes.

The server will take care of updating the appropriate zone automatically.


subnet .... {
   ddns-domainname = "pcs.testzone.intra";

subnet .... {
   ddns-domainname = "ipphones.testzone.intra";

So in fact the server never has to update anything other than 
ddns-domainname so the question is the wrong question for the problem 
You almost never need to alter ddns-rev-domainname.

If you allow updates by IP address then you do not even need any zone 
declarations in the dhcp config, it will automagically find the 
master server (it uses the authoritative server identified in the SOA 
record). If you do secure updates (ie by key) then you will have to 
define each zone, which is not necessarily the same as each domain 
name used.

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