Lane Redundancy Planning - 3Com CoreBuilder 9000 User Manual

400 C 15: LAN E
HAPTER
LANE Redundancy
Planning
MULATION
Consider the following issues when you plan your network to support
LANE redundancy:


Allow for route recovery in case of switch or link failure to provide
ATM address structure and physical network connectivity.


Do not allow primary and secondary LESes for an ELAN to be on the
same switch.


If possible, do not configure the primary LECS shown a switch with
primary LESs.


Do not clump too many primary LESs on a single switch. Distribute
LESs across the backbone
There is an important pre-condition for LANE redundancy to operate
correctly. Under some circumstances, some LECs cannot bind to the
backup LES even when they get the correct information about the
backup LES from the LECS. This may be due to problems with route
redundancy. Ensure that ATM re-routing works even when some links or
a switch are down. If a LEC cannot bind to the backup LES, check if the
LEC can connect to the LES and if the LES can, in turn, connect back to
the LEC. Correct E-IISP planning for route failover/redundancy is required
for LANE redundancy to work.