Microsoft Lync Server 2010 : Using Operating System Firewalls with Lync Server

In Windows Server 2003 SP1, Microsoft introduced an integrated firewall into the Windows operating system. As with most Microsoft products, it has improved with each iteration. Flash forward to Windows Server 2008 and you find that the integrated firewall is quite good. Lync Server does an excellent job of integrating into the Windows Server Firewall at the time of installation.

Layering an operating system layer firewall with a network layer firewall is an excellent way to improve overall security of a system with minimal expense. By layering these two together, if the network firewall becomes compromised, the attacker has to pierce the OS layer firewall to compromise the systems. Similarly, given that many attack vectors can come from within the company itself, the OS layer firewall offers protection from trusted systems that might become compromised.

Configuring the Windows Server 2008 Firewall for Lync Server

If the Windows Firewall is enabled and started at the time of installation of Lync Server components, the necessary exceptions will be created automatically.

For administrators who installed Lync Server without the firewall on and want to enable it and backfill the rules, Table 1 details the rules created to support various Lync Server roles.