Ip-Alive; Mac-Based Communication - Siemens SCALANCE W786-xPRO Operating Instructions Manual

the second wireless interface if no data transfer is possible on the first wireless interface.
The user is informed of the status of the redundant connection with the statuses "not
connected", "connected", or "error" (communication error).
5.1.6

IP-Alive

Application-related connection monitoring
The IP-Alive function provides application-related connection monitoring of the wireless link.
It is useful to use IP-Alive on IP connections when it is known that they are used to send
data cyclically. With IP-Alive, you specify a monitoring time for an IP address and a port. If
you do not want to monitor a particular port but rather only the data traffic from a particular IP
address, simply enter 0 in Port. This resets the monitoring with each frame from this IP
address.
In contrast to the Link Check, the SCALANCE W78x does not start any checks until the
monitoring time has elapsed. The SCALANCE W78x checks passively whether
communication took place during the specified monitoring period. As with Link Check, you
can also enter up to ten connections here.
5.1.7

MAC-based communication

Auto Find Adopt MAC / Adopt MAC manually
Frames in the direction from the client to the access point always have the MAC address of
the WLAN interface as the source MAC address. As a result, the learning table at the access
point end always has only the MAC address of the WLAN interface of the client. If the MAC
address of a device connected to the client is adopted, both the MAC-based and the IP-
based frames find their destination in precisely this device.
Other nodes located downstream from the client cannot be reached. The access point
checks whether the destination MAC address matches the MAC addresses of the connected
clients. Since a client can only adopt one MAC address, the access point does not find a
match and discards the packets of several nodes.
Maximum possible number of MAC nodes downstream from the client: 1
Notes on the "Auto Find Adopt MAC" setting:
● As long as there is no link on the Ethernet interface, the device uses the MAC address of
● As soon as there is a link on the Ethernet interface, the device adopts the source MAC
SCALANCE W786-xPRO
Operating Instructions, Release 08/2007, C79000-G8976-C221-02
the Ethernet interface so that it can be reached in this status. In this status, the device
can be found using the Primary Setup Tool.
address of the first received frame.
Configuration / project engineering
5.1 Technical basics
63