User guide

3-42 Packet Over SONET Module Installation and User Guide
Configuring the PoS Module
priority, which is an integer in the range from 0 to 7. To preserve the 802.1p priority,
do not enter the
priority keyword and value when using this command.
Default behavior is that tag nesting is disabled (off) for all VLAN IDs.
Tag push operations apply to egress frames only when the port is configured to
transmit tagged frames for the associated VLAN. Tag nesting operations apply only to
ingress frames that contain a VLAN tag. Tag nesting operations are applied after
classification to a QoS profile.
The default PPP MRU is sufficient for a single level of tag nesting (where the
frame contains two VLAN tags) between two Extreme Networks switches. If
higher levels of VLAN tag nesting are needed, jumbo frame support must be
enabled.
The DiffServ and RED functions are not performed by PoS ports when frames
contain nested tags (more than one tag).
Generic VLAN Registration Protocol Functions
The Generic VLAN Registration Protocol (GVRP) is not supported on PoS module
ports, so the following command will not work if you specify a PoS port:
config gvrp {listen | send | both | none] ports <portlist>
Configuring Forwarding Database Attributes
PoS ports support all of the existing ExtremeWare forwarding database (FDB)
commands. For more information on these commands, see the ExtremeWare Software
User Guide.
Configuring Spanning Tree Attributes
PoS ports support all of the existing ExtremeWare Spanning Tree commands.