Bridge Modes

Typical configurations for the use of the MC wireless client adapter

The MC WLAN-Client-Adapter is used to connect one or more devices with an Ethernet interface via a WLAN infrastructure to a stationary network.
The MC offers various bridge modes to meet application-specific requirements

Bridge mode LAN-Clients IP's im WLAN Transparency Note
LAN Client Cloning 1 1 (LAN Client IP) all ports IP- and MAC-address of the LAN-Client is registered in the WLAN.
Single Client NAT 1 1 (MC IP) all ports

IP- and WLAN-MAC-address of the MC is registered in the WLAN.
NAT as many 1 (MC IP) Ports def.
by config		 IP- and WLAN-MAC-address of the MC is registered in the WLAN.
Level 2 Bridge as many n LAN-Clients + 1 all ports All LAN-Client-IP's and the MC-IP are registered with the WLAN-MAC-address of the MC.
MWLC-Mode as many 1 (MC IP) all ports

Only the IP- and the WLAN-MAC-address of the MC is registered in the WLAN.

LAN Client Cloning Mode

In this mode the device connected to the LAN port of the MC determines the IP- and the MAC-address of the WLAN connection that the MC establish to the WLAN infrastructure. The configuration and monitoring of the MC is done via the IP address of the LAN-Client.

If only one LAN client is connected to the MC, this mode should be preferred.

LAN Client Cloning

Advantages

  • In the WLAN network, the MC will appear along with only with one IP address.

Disadvantages

  • Only one LAN-Client can be connected to the MC.

NAT- and Single-NAT Mode

The NAT mode is characterized in that the LAN clients connected to the MC work in a separate network from the wireless network. The traffic of the LAN clients via WLAN to the stationary network is transformed by the MC, so that all data is sent and received via the IP address of the MC.

NAT Mode

What to consider:
If only one LAN client is connected to the MC, the "Single Client NAT" mode should be used. In this mode the LAN client can be reached better without further configurations.

If multiple LAN clients are connected to the MC the NAT mode must be defined.
When the LAN clients offer server services that are addressed via WLAN, the used ports has to be defined in a port forwarding table.

Advantages

  • Any number of LAN clients can be connected to a MC
  • The MC with all LAN-Clients appear only with one IP address in the WLAN.
  • If many units are working in a project, consisting of multiple LAN clients with an MC, the configuration for all units is the same. Only the IP address of the MC for the wireless side may need to be individually configured.
  • The LAN clients are better protected against unwanted access, because the MC switches through only data for the configured ports.
  • Local broadcast packets (on the LAN side of the MC) are not sent over the WLAN.

Disadvantages

  • Access to the LAN clients via WLAN is possible only on the ports defined in the NAT rules.
  • If LAN clients offer server services on the same port numbers (eg FTP), the user must define port forwarding rules in a way that these services are addressed on different ports for each LAN clients.

Level 2 Pseudo-Bridge Mode

In this mode, each LAN client communicates with its own IP address over the wireless network. However, all data is sent with the MAC address of the MC-WLAN card. This procedure can make problems in some WLAN infrastructure systems. Problems can appear when the  WLAN controller is working with ARP caching.

Level 2 Pseudo Bridge

Advantages:

  1. Any number of LAN clients can be connected to a MC.
  2. Good transparency of the LAN clients to the WLAN without configuration.

Disadvantages:

  1. The MC and all wireless clients work with their own IP addresses. These IP addresses must be in the same network.
  2. Problems in some WLAN infrastructures with centralized controllers (no accessibility to  the LAN clients from the WLAN side).

 

MWLC-Mode

With the MWLC mode, all restrictions on the availability, IP address assignment and transparency especially in applications with multiple LAN clients are solved. In this Mode all data packets received from the LAN-Clients are tunneled by the MC (Slave) to another MC (master) that is installed on stationary network side. The master MC extract the LAN-Client data packets and send it into the stationary network. 
 
MC Bridge MWLC Mode1

In this mode the IP addresses of the LAN clients has no influence to the MC. The LAN-Clients are connected to the stationary network with there own IP- and MAC addresses. Because the MWLC master in this constellation plays a central role, and a failure of this device would disconnect all clients, there is the possibility to install a 2nd MWLC master as a backup.

Advantages

  • Maximum connection transparency for the LAN clients via WLAN into the stationary network.
  • The configuration work to the MC doesn't depend on the amount of LAN clients.

Disadvantages

  • On the stationary network side one or two additional MC adapter are needed . 

For a more detailed description of these modes, refer to the MC Manual.