Firewall Traversal And Dual Network Interfaces - Cisco TelePresence Administrator's Manual

Firewall traversal

Firewall traversal and Dual Network Interfaces

The Dual Network Interfaces option key enables the LAN 2 interface on your VCS Expressway (the option is
not available on a VCS Control). The LAN 2 interface is used in situations where your VCS Expressway is
located in a DMZ that consists of two separate networks - an inner DMZ and an outer DMZ - and your
network is configured to prevent direct communication between the two.
With the LAN 2 interface enabled, you can configure the VCS with two separate IP addresses, one for each
network in the DMZ. Your VCS then acts as a proxy server between the two networks, allowing calls to pass
between the internal and outer firewalls that make up your DMZ.
Note: all ports configured on the VCS, including those relating to firewall traversal, apply to both IP
addresses; it is not possible to configure these ports separately for each IP address.
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