Configuring NIC for passive recording (port mirroring)

Note, the instructions in this document do not apply to active recording methods, like Cisco Built-in-Bridge, SIPREC, etc.

Usually, the same network interface adapter (NIC) can be used for both port mirroring traffic and regular access of the server from a network.

But in some cases it is recommended (or even required) to install a separate NIC, which will be used solely for port mirroring purposes. These cases are following:

  • More than 50 concurrent calls are recorded by MiaRec at the same time
  • The switch discard network packets on a port, which is used as a destination for port mirroring session
  • DHCP or DNS services are running on the same server, when MiaRec is running.

In these cases MiaRec should be connected to network switch with two NICs as shown on below diagram:

MiaRec Server with two NICs

  • The first NIC will be dedicated to port monitoring traffic
  • The second NIC will be used for a remote access of the server from other computers.

To prevent any conflicts with IP-addresses the first NIC should be switched to "stealth" mode with TCP/IP unbound from the card. You will need to open properties of NIC and disable IP stack and all other protocols (see below screenshot). This NIC will be used in listen mode only. No network packets will be sent from this NIC. That's why IP address is not necessary for it.

Listen-only configuration