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"Unicast-flood" is a phenomenon which occurs  occurs when the frame's destination MAC-address is unknown for the switch (not included in its address tablerouting table), the unit it sends this frame to all interfaces of the network, except for the besides the sender interface. The most common reasons of unicast-flood are:

• MAC address table overflow (a common problem in large networks);
• Hosts with ARP timers greater longer than the ARP cache timeouttime on switches;
• Incorrect STP settings;
• Incorrect switch groups settings (in particular, when the numbers IDs of switch groups for receiving and sending traffic are different).

The unicast-flood process on R5000 devices looks like thisis the following: if the frame's destination MAC-address is not included in the device MAC switch group's MAC address forwarding table, then this frame is sent out in all interfaces except the sender interface. The distribution occurs until the device receives a frame with this MAC address as the sender (i.e., the interface to which the packet was destined destinated to respond). After that, the R5000 will learn: add it will add this MAC address to the MAC switch group MAC address forwarding table and fix it  and map it with the interface from which it was received. If the R5000 does not learn in 4 seconds, and frames still arrive, then traffic to this direction will be blocked for 4 seconds. Then the process repeats.

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Scroll Title title Figure - Unicast-flood example in the unit's interfaces graphicsgraphs

Also, unicast-flooding can be detected in the "Switch Statistics" → "Device Status" tab in "Flood" column:

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InfiNet Wireless units provide unicast-flood protection. If necessary, you can allow unlimited unicast-flood without protection filter filter through the switch group by setting the check box in "Basic Settings" → "MAC Switch settingsSwitch" settings:

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