Alcatel Carrier Internetworking Solutions Switch/Router 사용자 설명서

Page 18-15

For the Ethernet one further distinction is made. If the frame received from the backplane is 
an Ethernet media type frame from another Ethernet switching module in the same chassis, 
then no encapsulation translations are applied. Such frames are referred to as Native frames.

If the frame is of an Ethernet media type but was put onto the backplane by some other type 
of switching module, for example, the frame came from a FDDI card via a trunk port, or from 
the MPX via routing, then encapsulation translations are applied. Such frames are referred to 
as Non-Native frames.

♦ Important Note ♦

The 

 file contains a command called 

 

that by default is set to 

. If your switch uses multiple 

encapsulations (for example, VLAN 2:1 is 802.3 IPX and 
VLAN 3:1 is Ethernet II IPX) then the 

 

command must be set to 

. See Chapter 7, “Managing 

Files,” for more information on the 

 file.

For FDDI, Token Ring and LAN Emulation on ATM, a native/non-native distinction is not 
made. Instead, no encapsulation translations are applied by these switching modules to 
frames which are of their own media type.

Switching modules which support encapsulation mechanisms, such as Trunking ports on 
FDDI and Token Ring, and Point to Point ports on ATM do not apply translation to frames 
destined to such ports.

All other aspects of the transformation process are driven by the media type of the frame, the 
media type of the port on which the frame is to be transmitted and the protocol type deter-
mined for the frame. Thus frame padding insertion/stripping, IP fragmentation, IP ARP bit 
swapping, etc., are all automatic.

The one area which remains configurable is the bit swapping of source addresses for IPX in 
order to allow Token Ring to work with FDDI and Ethernet. This is the equivalent function to 
IP ARP bit swapping.

This option is configurable and by default is on.