3Com CoreBuilder 9000 User Manual page 397

LAN Emulation Redundancy 397
The newly activated secondary LES remains active even after the failed
primary LES becomes operational again. You can cause the primary LES to
become the active LES again by using an LMA command. (See "Make
Primary LES Active" on page 266.) You need to perform this command
on all CoreBuilder 9000 ATM Enterprise Switches with active LECS and
verify the result.
Normally, since their topology database is identical, all LECS in the
network respond in the same way to a LES failure; they each assign the
same secondary LES to replace a failed active primary LES and the
topology databases remain the same. The split ELAN is an exception; it is
discussed in the next section.
If neither primary LES nor secondary LES can be made active, an error
message is issued to a LEC whenever it tries to join the network.
Note that when a primary LES for which no secondary LES is defined fails,
the LECS continues attempting to assign a requesting LEC to the ELAN
until the LEC stops requesting.