3Com S7906E Configuration Manual page 2591

Figure 1-7 Network diagram for BFD MAD detection
LACP MAD requires intermediate devices that are capable of identifying and processing LACP data
units (LACPDUs) extended to carry the Active ID field.
Enabling BFD MAD detection
BFD MAD detection is implemented through the BFD protocol. You need to enable BFD detection on a
Layer 3 interface and configure the MAD IP address on the interface. A MAD IP address is different from
a common IP address: a MAD IP address is bound to a member device; and all member devices in the
IRF need their own MAD IP addresses, which are on the same network segment. However, only the
MAD IP address on the master is effective, and the MAD IP addresses on the slaves are not effective.
When the IRF operates normally, only the MAD IP address of the master is effective and the BFD
session is down.
When the IRF splits into two or multiple IRFs, all the MAD IP addresses of the masters in different
IRFs are effective, the BFD session is activated, and multiple active IRFs are detected.
Follow these steps to enable BFD MAD detection:
To do...
Enter system view
Create a VLAN used for BFD
MAD detection
Quit system view
Enter VLAN interface view
Enable BFD MAD detection
Configure the MAD IP address
for the Layer 3 interface on the
specified member device
Quit system view
Use the command...
system-view
vlan vlan-id
quit
interface interface-type
interface-number
mad bfd enable
mad ip address ip-address
{ mask | mask-length } chassis
chassis-number
quit
1-15
Remarks
—
Required
By default, only VLAN 1 is
created.
—
—
Required
Disabled by default.
Required
By default, no MAD IP
address is configured for the
interface.
—