Cabletron Systems 6500 - Manual (Page 55)

SmartSwitch 6500 User Guide 3-7
IP Over ATM and LANE Creating an Emulated LAN
netprefix + chassis MAC address + ELAN number summed with the numerical value two (2)
For example
• netprefix = 39:00:00:00:00:00:00:00:00:00:A3:87:0B
• chassis MAC address = 00:00:1D:A3:87:0B
• ELAN number = 3
then,
default LES and BUS addresses = 39:00:00:00:00:00:00:00:00:00:00:00:1D:A3:87:0B:05
3.2.2 ELANs Across Multiple Switches
ELANs can exist within a single switch, or they can span multiple switches. When an ELAN spans multiple switches,
it’s important that all switches within the group use the same LECS. The general rule is: “Within an administrative
domain (a group of switches with related ELANs), there should be one and only one LECS.” For this reason, never
start the LECS on more than one switch within the administrative domain.
Note If an uplink, end node, or other ATM switch does not support PNNI, or if its
version of ILMI is incompatible, it may be necessary to set up a static route
between the device and the rest of the ELAN. See Chapter 5, "Routing."
3.2.3 Switch Clients
It is important to understand the concept of SmartSwitch 6500 client connections. A client connection is actually a
connection between the VLAN and the SmartSwitch 6500 CPU; this CPU connection appears as if the switch is an
end station on the VLAN. The SmartSwitch 6500 uses local clients to connect itself to the VLANs that it supports.
This is analogous to a phone company that supports a communication system. Even though the phone company
maintains the circuits, a call to the phone company itself cannot be made unless the phone company has its own number
and connection on its own phone system. Similarly, VLAN membership (and the reachability) of a SmartSwitch 6500
on any particular VLAN depends upon whether the SmartSwitch 6500 has a local client connection for that VLAN.
Clients are created using the command add laneclient for LAN emulation, and add ipatmclient for IP over ATM.
For example, the following command adds a switch client to the ELAN elan1:
SmartCell ZX# add laneclient
ClientNumber(0) : 1
LanName(ELAN001) : elan1
ServerType(LECS) :
ServerAddress() :
IPAddress() : 128.213.77.95
NetMask(255.255.0.0) :
MTU(1516) :
SmartCell ZX#
Prior to creating this local client connection, end devices could communicate with each other through elan1 , but they
could not communicate with the SmartSwitch 6500.