I’ve deployed a lot of Lync Phone Edition devices. Thing is, I’ve done so mainly in smaller environments where we used either a Standard Edition Front-end server or an Enterprise “pool” that consisted of a single server. Why is this important you ask? Well, let’s go to one of the best articles on DHCP Option 43: http://blog.schertz.name/2012/05/understanding-dhcp-option-43/

In Jeff’s article, he has this paragraph in the middle of it:

If multiple Lync servers are deployed in the environment then the _SipServer _parameter may need to be defined as a Lync Pool FQDN (in the case of an Enterprise Edition deployment).  Additionally if any load balancing is configured on the Front End pool and the Internal Web Services FQDN is different than the Pool FQDN (in the case of DNS Load Balancing) then an additional switch of _WebServer _needs to be used to provide the Web Services FQDN.  If the WebServer swtich is not provided the command uses the _SipServer _value by default for both the registrar and web services location. Additionally if a Director Server or Pool is in place then the Director FQDN is typically defined as the _SipServer _parameter (and the _WebServer _parameter is not needed).

This is a key piece of information. If you don’t have a director in place and you are load balancing the Internal Web Services (via a HLB and you’ve over-ridden the Internal Web Services FQDN), then you need to run DHCPUtil.exe with the “-webserver” switch. Example: “dhcputil.exe -sipserver mylyncpool.domain.com -webserver mylyncwebservices.domain.com”.

What this will do is change sub-option 003 to use the Internal Web Services name instead of the pool name (which you set with the “-sipserver” switch).

I had to be reminded of this lately and decided I should write about it in order to try and commit it to memory.