Alcatel Carrier Internetworking Solutions Omni Switch/Router - Manual (Page 517)

The User Interface
Page 18-21
The SNAP Option
This option can be applied to all media type ports and is set to the following:
In the modvp or addvp commands for FDDI and Token Ring the only choices other than
default are SNAP or LLC and the default must be one of these. As the factory default is SNAP
with IPX 802.2 Pass through and the SNAP does not imply pass through the additional ques-
tion about pass through is not asked on FDDI and Token Ring ports as the preference can be
expressed by choosing default or SNAP explicitly.
Ethernet Media - SNAP Mode
No translation is performed on outbound Ethernet frames where
the inbound interface was Ethernet.
IP frames are transmitted as SNAP frames.
All IPX frames are transmitted as SNAP frames.
No translation is performed on Appletalk frames, and we
currently support only Appletalk Phase II (SNAP format).
Other than IP and IPX, all other Ethernet II or SNAP frames are
transmitted as SNAP frames.
Other IEEE 802.2 with LLC are not translated.
FDDI / Token Ring Media - SNAP Option
No translation is performed on outbound FDDI or Token Ring
frames where the inbound interface was the same media type.
IP frames of any encapsulation type are transmitted as SNAP
frames.
IPX frames received that do not have an IEEE 802.2 encapsula-
tion type, are transmitted as SNAP.
IPX frames received that are of IEEE 802.2 encapsulation type
are transmitted as SNAP if the LLC passthrough is disabled. If the
LLC passthrough is enables, these frames will not be translated.
No translation is performed on Appletalk frames, and we
currently support only Appletalk Phase II.
All other LLC encapsulated protocols are left as is.