H3C Technologies H3C S10500 Series Switches - Manual (Page 28)

Configuring MAD detection
You have the following MAD mechanisms for detecting multi-active collisions in different network
scenarios:
• LACP MAD
• BFD MAD
These MAD detection mechanisms operate independently, and you can configure all of them for an IRF
fabric.
Configuring LACP MAD
1. LACP MAD detection mechanism
With LACP MAD, an IRF member switch sends extended LACP data units (LACPDUs) with a type length
value (TLV) that conveys the domain ID and active ID of the IRF fabric for detecting an IRF split. The
domain ID uniquely identifies an IRF fabric in the network, and the active ID is identical to the member
ID of the master switch in the IRF fabric.
An IRF member switch compares the domain ID and the active ID in each received extended LACPDU
with its domain ID and active ID:
• If the domain IDs are different, the extended LACPDU is from a different IRF fabric, and the switch
does not continue to process the extended LACPDU with the MAD mechanism.
• If the domain IDs are the same, the switch compares the active IDs:
{
If the active IDs are different, the IRF fabric has split.
{
If the active IDs are the same, the IRF fabric is operating normally.
2. Network requirements
Every IRF member switch has a link with an intermediate switch, and all these links form a dynamic link
aggregation group, as shown in Figure 9 .
The intermediate switch must be an H3C switch capable of handling extended LACPDUs that carry the
Active ID field. For more information about LACP and the support of the switch for extended LACPDUs,
see Layer 2—LAN Switching Configuration Guide.
CAUTION:
If the intermediate switch is in an IRF fabric, you must assign this fabric a different domain ID than the
LACP MAD-enabled IRF fabric to avoid false detection of IRF partition.
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