Configuring Ethernet Settings; Configuring Dns Settings - Cisco TelePresence Video Communication Server Administrator's Manual

The External LAN interface field indicates which LAN port has been connected to your external
network. It also determines the port from which TURN server relay allocations are made.
About Dual Network Interfaces
The Dual Network Interface option key enables the LAN 2 port on the VCS Expressway for both
management and call signaling. This allows you to have a second IP address for your VCS.
This configuration is intended for high-security deployments where the VCS is located in a DMZ
between two separate firewalls on separate network segments. In such deployments, routers prevent
devices on the internal network from being able to route IP traffic to the public internet, and instead the
traffic must pass through an application proxy such as the VCS.
To enable this feature you must purchase and install the appropriate option key. Contact your Cisco
representative for information.
Note: you should configure the LAN 1 port and restart the VCS before configuring the LAN 2 port.
If you have Dual Network Interfaces enabled but only want to configure one of the Ethernet ports, you
must use LAN 1.
About static NAT
It is possible to deploy a VCS Expressway behind a static NAT device, allowing it to have separate
public and private IP addresses. This feature is intended for use in deployments where the VCS
Expressway is located in a DMZ, and has the Dual Network Interfaces feature enabled.
In these deployments, the externally-facing LAN port has static NAT enabled in order to use both a
private and public IPv4 address; the internally facing LAN port does not have static NAT enabled and
uses a single IPv4 (or IPv6) address.
In such a deployment, when configuring traversal clients to use the VCS Expressway as a traversal
server, it is the latter internally-facing IP address of the VCS Expressway that should be used. To
enable the use of a static NAT:
1. Ensure that the Dual Network Interfaces option key is installed.
2. For the externally-facing LAN port:
a. In the IPv4 address field, enter the VCS Expressway's private IP address.
b. Select an IPv4 static NAT mode of On.
c. In the IPv4 static NAT address field, enter the VCS Expressway's public IP address - this is
the IP address of the outside of the NAT.

Configuring Ethernet settings

The Ethernet page (System >
VCS and the Ethernet switch to which it is connected. The speed must be set to the same value on
both systems. If you have the Dual network interfaces option enabled, you can configure the
Ethernet speed separately for each LAN port.
The default is Auto, which means that the two systems will auto-negotiate the appropriate speed.
Note: you are recommended to use the default value of Auto unless the switch to which you are
connecting is unable to auto-negotiate. A mismatch in Ethernet speed settings between the VCS and
Ethernet switch will at best result in packet loss; at worst it will make the system inaccessible for
endpoints and system administrators.

Configuring DNS settings

The DNS page (System >
Cisco VCS Administrator Guide (X6.1)
Ethernet) is used to configure the speed of the connection between the
DNS) is used to configure the VCS's DNS servers and DNS settings.
Network and system settings
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