Operation Manual

ATM Administration
72
ELAN Membership
The following steps determine which ELAN a device can join during normal
network operations.
There are FOUR ways to define ELAN membership:
1. When a new device is seen, your switch (LEC) requests configuration
information from the LECS. If a MAC address has been preconfigured
with the LECS, the LECS will send an acknowledgement message to your
LEC and the desired ELAN will be assigned.
2. Your switch (LEC) requests configuration information from the LECS. If
a MAC address has NOT been preconfigured with the LECS, the LECS
will send a rejection message.
3. Your switch (LEC) requests configuration information from the LECS. If
the MAC address has NOT been preconfigured with the LECS, the LECS
will send a rejection message.
The LECS will then assign that LEC to the default ELAN for the port.
Note that any or all ports can have “default” ELANs assigned by sending
a Configuration Request to the LECS for each, or all, port(s) that you
want assigned to the “default” ELAN. The LECS, in turn, will then assign
that LEC to the default ELAN for the port — IF a default ELAN has
been assigned.
See Default ELAN on page 70.
In short, there are two ways that a port can be assigned to the default
ELAN. One way is through Omega. The second way is to not use Omega
but through a configuration request at initialization using the port’s MAC
address.
If a default ELAN has NOT been assigned to a port, the ELAN for all
devices attached to that port MUST be configured by the LECS. This
means that every device attached to that port will have the same ELAN.
4. Your LEC can also be assigned with a “FIXED ELAN” configuration. A
“FIXED ELAN” simply means that all devices attached to a port will join
the ELAN that has been predetermined by the LECS or is configured for
the port.