IBM SG24-4817-00 manual Maximum SDU Size, Elan Name, LEC Parameters, Ethernet Type, IP Address

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Specify the maximum number of LECs supported by the designated

LES/BUS. The maximum number is 128 and is the sum of both

LES/BUSes when two LES/BUSes are configured.

−Maximum SDU Size

Specify the maximum AAL-5 service data unit (SDU) size supported by the designated LES/BUS. The SDU is the information part of AAL-5 protocol data unit (PDU). The possible values are 1516, 4544, 9234 and 18190 (default: 1516) regardless the ELAN type.

Note

On a real Ethernet network, the maximum data frame length is 1492 or 1500 bytes. However, up to 18190-byte frames are supported on an ELAN as stated above. You may know the inconsistency with the

length field in an IEEE 802.3 frame which should be less than 1536 (X′0600′). But the inconsistency is resolved on the the IEEE 802.3

LANE by placing the value 0 in the length field when the IEEE 802.3 LANE frame is longer than 1536.

On the other hand, you must specify 1516 for the maximum SDU size when your ATM network attached to a real Ethernet network via an ATM bridge which doesn′t have fragment capability.

−ELAN Name

Specify the Emulated LAN name. The default value is

IBM_lantype_LANn, with lantype set to ETHERNET or TOKEN_RING based on the ELAN type, and n set to 1 or 2 based on the server ID. For example, the default ELAN name for the Ethernet LES/BUS with server ID 1 is IBM_ETHERNET_LAN1.

•LEC Parameters

The integrated LEC function supports the TCP/IP protocol over

Forum-Compliant LAN Emulation and provides a node management interface to a Telnet station or to a SNMP manager.

To configure the LEC, use the SET DEVICE LAN_EMULATION_CLIENT command with the following parameters:

−ELAN Type

Specify the ELAN type to which the LEC belongs. The valid options are ETH (Ethernet LANE) or TR (token-ring LANE).

−Ethernet Type

Specify the Ethernet type when the ELAN type is Ethernet. The default setting is 802.3 and the Ethernet type should be the same as the communicating device. Note that there are many devices that have the other Ethernet type (DIX/Ethernet V2) as the default.

−IP Address

The IP address to be assigned to the switch. This must be unique. And if the IBM 8285 is configured with multiple IP addresses, they have to be on different IP networks because they are treated as the IP interfaces of an IP node.

Chapter 7. IBM 8285 Configuration 133