IBM SG24-4817-00 manual Configuring a Simple Lane Network, Lecs / IBM 8285 Addressing

This soft copy for use by IBM employees only.

It is not necessary to pre-define the LECS′ address on each LEC definition if you have a LECS since the mechanisms by which the LECs dynamically use a specific ATM address of the LECS are standardized.

When the 8285 LEC is attached to this type of ELAN, the SET DEVICE LAN_EMULATION_CLIENT command with the parameter NO_LES_WITH_LECS followed by NONE is used to get the LECS ATM address dynamically. The IBM 8285 will search for the LECS ATM address, first using ILMI. If it does not find it, then it will try using the LECS well-known address (WKA) as specified in the standard. To use the dynamic LECS ATM address resolution, you must not forget to define the specific ATM address of LECS in the IBM 8285 definition using the SET LAN_EMUL CONFIGURATION_SERVER command.

The LEC automatically starts when the SET DEVICE

LAN_EMULATION_CLIENT command is issued and it cannot be stopped after starting. If you really need to clear the LEC parameters, you should clear the parameters using CLEAR CONFIGURATION command in maintenance mode.

•LECS / IBM 8285 Addressing

The IBM 8285 doesn′t have the LECS but does interwork with the external LECS. When you have an external LECS and resolve the specific ATM address of LECS dynamically, such as using ILMI and well-known Address (WKA), you have to define the real ATM address of it to register it on the LECS address table in the IBM 8285.

To register the real ATM address of LECS, use the SET LAN_EMUL CONFIGURATION_SERVER command with the following parameter:

−ACTIVE_WKA or INACTIVE_WKA

The LECS address table contains an ATM address to be substituted for the WKA. You can define the specific ATM address of WKA as Active WKA. In an 8285, you can define only one active WKA entry. But you can also define 4 Inactive WKA entries in addition. The ACTIVE_WKA or INACTIVE_WKA option is followed by the specific ATM address of it. The ACTIVE_WKA option replaces current Active WKA.

Note

As described above, the SET LAN_EMUL CONFIGURATION_SERVER command is used to define the specific ATM address of LECS for ILMI MIB. Then the active WKA has no meaning and all entries defined on the table are included in the MIB in the order of index (Index 1 should be top of the ILMI MIB entries). It means that you can have LECS redundancy by defining multiple LECSs, which have the same configuration on the IBM 8285/8260s in your campus ATM network.

7.2.3 Configuring a Simple LANE Network

Figure 42 on page 136 and Figure 43 on page 136 show a simple LANE network, both physically and logically, comprised of an IBM 8285 and workstations.

Chapter 7. IBM 8285 Configuration 135