Thursday, October 2, 2014

Routing interfaces, devices, and ports

Routing interfaces, devices, and ports

Routing and Remote Access views the installed networking equipment as a series of routing interfaces, devices, and ports.
  • A routing interface is a physical or logical interface over which unicast or multicast packets are forwarded.
  • A device represents hardware or software that creates physical or logical point-to-point connections.
  • A port is a communication channel that supports a single point-to-point connection.

Routing interface

The server running Routing and Remote Access uses a routing interface to forward unicast IP or AppleTalk packets and multicast IP packets. There are two types of routing interfaces:
  • LAN interfaces

    A LAN interface is a physical interface that typically represents a local area connection that uses local area networking technology such as Ethernet or token ring. A LAN interface reflects an installed network adapter. An installed WAN adapter is sometimes represented as a LAN interface. For example, some Frame Relay adapters create a separate logical LAN interface for each configured virtual circuit. LAN interfaces are always active and typically do not require an authentication process to become active.
  • Demand-dial interfaces

    A demand-dial interface is a logical interface that represents a point-to-point connection. The point-to-point connection is based on either a physical connection, such as two routers connected over an analog phone line that uses modems, or a logical connection, such as two routers connected over a virtual private network connection that uses the Internet. Demand-dial connections are either on-demand (the point-to-point connection is only established when needed) or persistent (the point-to-point connection is established and then remains in a connected state). Demand-dial interfaces typically require an authentication process to become connected. The equipment needed by a demand-dial interface is a port on a device.
You can view the installed and configured routing interfaces by clicking Network Interfaces in Routing and Remote Access.


A device is the hardware or software that provide ports that demand-dial and remote access connections use to establish point-to-point connections. Devices can be physical, such as a modem, or virtual, such as virtual private network (VPN) protocols. Devices can support a single port, such as a modem, or multiple ports, such as modem bank hardware that can terminate 64 different incoming analog phone calls. An example of a virtual multiport device is the Point-to-Point Tunneling Protocol (PPTP) or Layer Two Tunneling Protocol (L2TP). Each of these tunneling protocols supports multiple VPN connections.
You can view the installed devices by viewing the properties of Ports in Routing and Remote Access.


A port is a channel of a device that supports a single point-to-point connection. For single-port devices such as modems, the device and the port are indistinguishable. For multiport devices, the port is the subdivision of the device over which a separate point-to-point communication is possible. For example, Primary Rate Interface (PRI) ISDN adapters support two separate channels called B channels. The ISDN adapter is a device. Each B channel is a port because a separate point-to-point connection occurs over each B channel.
You can view the installed ports by clicking Ports in Routing and Remote Access.


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