Alcatel-Lucent AOS-W 6.5.3.x - Page 1042

allocation. If the branches are deployed in local only or centralized l2 only modes, the BID allocation process is
not required.
The BID allocation process performs the following functions:
n Determines the IP addresses used in a branch for distributed L2 mode
n Determines the subnet used in a branch for distributed L3 mode
n Avoids IP address or subnet overlap (that is, avoids IP conflict)
n Ensures that a branch is allocated the same subnet or range of IP addresses irrespective of which AP in the
branch assumes the role of the master in an IAP cluster
BID Allocation in a Master-Local Topology
In a master-local switch setup, the master switch runs the BID allocation algorithm and allocates BID to the
branches terminating on it and the Local switches. The IAP sends the new branch registration requests to the
Local switch (branch coming for the first time with BIDs as -1), which in turn forwards the request to the master
switch. After receiving the registration request, the master switch allocates BIDs to the local switch and local
switch sends the BID details to the IAP. The master switch saves the BIDs in its memory and the IAP database
to avoid the collision of BID (per subnet), whereas the local switch saves the BIDs only in its memory.
Trusted Branch Validation
The branch registration requests sent by the IAP indicates whether the IAP is managed by OmniVista or Central,
and provides information about the IAP configuration modes on AirWave (managed or monitored modes).
Based on the information received in the registration request and the status of trusted branch configuration,
switch allows the IAP to register the branch.
Table 257 maps the IAP configuration scenario to the branch registration and trusted branch validation
process.
IAP Configuration Mode on
OmniVista or Central
Trusted Branch DB
validation Enabled on
Switch
Branch Registration
Allowed?
Monitor mode Yes
No
Monitor mode No
Yes
Managed mode Yes
Yes
Managed mode No
Yes
Not managed by OmniVista or
Central
Yes
No
Not managed by OmniVista or
Central
No
Yes
Table 257: Branch Registration and Trusted Branch Validation
To enable trusted branch DB validation:
n Ensure that the IAPs are running Instant 4.0 or later.
n Ensure that the switch is upgraded to AOS-W 6.4 or later.
AOS-W 6.5.3.x | User Guide Instant AP VPN Support | 1042