Configuring Igmp Attributes - Extreme Networks BlackDiamond 6800 Installation And User Manual

Configuring the ATM Module
• No frames received from the switch backplane will be discarded due to being too
large. Nor will any IP frames be fragmented.
• PDUs received from the ATM link with routed protocol encapsulation will be
discarded if the size of the IP packet exceeds (configured JUMBO_FRAME_MTU -22)
octets.
• PDUs received from the ATM link with bridged protocol encapsulation will be
discarded if the size of the Ethernet frame (including a VLAN tag but excluding the
LAN FCS) exceeds (CONFIGURED JUMBO_FRAME_MTU - 4) octets. If the Ethernet
frame does not include a VLAN tag field, then the frame will be discarded if the size
of the Ethernet frame (excluding the LAN FCS) exceeds (CONFIGURED
JUMBO_FRAME_MTU - 8) octets.
If jumbo frame support is not enabled on an ATM port, the following can occur:
• Frames received from the switch backplane, whose size exceeds 1522 octets, will not
be forwarded onto the ATM link. IP frames that meet this criteria will be sent to the
MSM CPU for fragmentation/Path MTU Discovery processing. Non-IP frames that
meet this criteria will be discarded.
• PDUs received from the ATM link with routed protocol encapsulation will be
discarded if the size of the IP packet exceeds 1500 octets.
• PDUs received from the ATM link with bridged protocol encapsulation will be
discarded if the size of Ethernet frame (including a VLAN tag but excluding the
LAN FCS) exceeds 1518 octets. If the Ethernet frame does not include a VLAN tag
field, then the frame will be discarded if the size of the Ethernet frame (excluding
the LAN FCS) exceeds 1514 octets.
Consider these factors when configuring jumbo frame support on an ATM port:
• When the jumbo frame size is changed from a value of 6129 or less to a value greater
than 6129, any ATM module that has ports with jumbo frame support enabled must
be rebooted for the change to take effect.
For more information on the ExtremeWare jumbo frame commands, see the
ExtremeWare Software User Guide.

Configuring IGMP Attributes

For more information on the ExtremeWare IGMP commands, see the ExtremeWare
Software User Guide.
3-48 Asynchronous Transfer Mode (ATM) Module Installation and User Guide