Skype for Business (Lync) device DHCP for Cisco IOS

Some PowerShell scripting

Posted on July 18, 2015


While designing a Skype for Business deployment for a customer, a requirement was discovered that meant we would need to provide a DHCP configuration to their WAN vendor. Each of the sites would be using Polycom VVX devices with IP addresses obtained from a Cisco router.

Neill Pert describes the process of taking output from DHCPUtil and massaging to a usable format but wouldn’t it be nice if we didn’t have to mess around with concatenating strings and counting lengths?

Introducing my first non-commercial contribution to the internets: Get-CsCiscoIosDhcp.ps1

Creating the Configuration

Fire up PowerShell and run the script:


The script will then ask for DHCP options needed for a successful Lync Phone Edition/Qualified deployment with PIN authentication:

DNS suffix (eg. contoso.local): contoso.local
UTC/GMT Offset Hours (eg. +/-10): 10
NTP server address (eg.
NTP server address (eg. 
DNS search domain (eg. contoso.local): contoso.local
DNS search domain (eg. contoso.local):
DNS search domain (eg. contoso.local):
SfB/Lync SIP FQDN (eg.
SfB/Lync Web FQDN (eg.


Cisco IOS DHCP configuration for the following values :
DNS suffix : contoso.local
Time Offset : 10
NTP Servers :
DNS Search List : contoso.local
SIP Server :
Web Server :
domain-name "contoso.local"
option 2 hex 00008ca0
option 42 ip
option 119 hex 07636f6e746f736f056c6f63616c0007636f6e746f736f03636f6d00
option 120 hex 000373697007636f6e746f736f03636f6d00
option 43 hex 010c4d532d55432d436c69656e7402056874747073030f7369702e636f6e746f736f2e636f6d040334343305252f4365727450726f762f4365727450726f766973696f6e696e67536572766963652e737663

Revision History

v0.1: 19 July 2015: Initial release


Download Get-CsCiscoIosDhcp.ps1


Configuring a Cisco ISR861’s DHCP Service for Lync Edition Handset -

Cisco support community post by Michael Solomonides describing option 119 -

Setting Up DHCP for Devices -