Egress Rules; Forwarding Process; Mac Thrash Limiting (Sbx); Duplicate Addresses On Inter-Card Interfaces (System Wide) - Allied Telesis SwitchBlade x3100 Series Manual

Introduction
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4.2.4 Forwarding Process

The Forwarding Process forwards received frames that are to be relayed to other ports in the same VLAN. If a
frame is received on the port for a destination in a different VLAN, it will need to be serviced by a Layer 3
switch/router external to the SBx3112 product.

4.2.5 Egress Rules

Once the Forwarding Process has determined which ports the frame is to be forward to, the Egress Rules for
each port determine if the outgoing frame is to be VLAN-tagged with its numerical VLAN Identifier (VID).
When an interface is added to a VLAN, the VLAN is configured to transmit either untagged or tagged VLAN
packets. This is done using the commands to add or set the VLAN interface. Refer to
4.2.6 MAC Thrash Limiting (SBx3112)
As explained in the previous sections, the four related processes listed in
directly to its proper destination with a system that maps VLANs to unique MAC addresses on specific inter-
faces. However, it is possible that duplicate MAC addresses can occur legitimately (called a MAC move), and
these can occur on different interfaces or on the same interface. The MAC Thrash Limiting feature detects and
handles this scenario where MAC moves occur at a high rate.

4.2.6.1 Duplicate Addresses on Inter-card Interfaces (System Wide)

If the same address is seen on more than one interface a number of times, there is a possible loop condition.
Any time a MAC move occurs, it is considered a potential duplicate address. When the first MAC move is
detected a system-wide one second timer starts. During this second, the MAC move count increments. If the
count exceeds 128 before the second expires, a duplicate address condition is declared and the following
actions occur:
The interface on which the next MAC move occurs is learning disabled. Packets received will continue to
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forward.
The interface will stay in a learning disabled state for 60 seconds.
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The interface that currently has the MAC address is not affected, and its learning is not disabled.
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Up until the second expires, these actions continue for every succeeding MAC move.
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An alarm is generated, and a trap is sent.
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When the second expires, the process for detecting MAC moves starts again.
4-4
Software Reference for SwitchBlade x3100 Series Switches (Layer Two Switching)
0.1 0A:37:F5:3A:50:B5
0.1 0C:1E:A0:ED:3E:23
0.1 0E:68:72:C3:CC:8E
0.1 10:2A:7E:46:55:B7
0.1 12:61:E5:FE:D3:00
0.1 16:31:91:FB:7B:5A
0.1 1A:3D:A3:21:66:53
Forwarding Process
Dynamic
Dynamic
Dynamic
Dynamic
Dynamic
Dynamic
Dynamic
4.4.2.1 on VLAN tagging.
4.2.1 result in traffic being sent