Users Guide

NOTE: In Standalone, VLT, and Stacking modes, you can configure a maximum of 16 members in
port-channel 128. In PMUX mode, you can have multiple port-channels with up to 16 members per
channel.
Uplink LAG
When the Aggregator power is on, all uplink ports are configured in a single LAG (LAG 128).
Server-Facing LAGs
Server-facing ports are configured as individual ports by default. If you configure a server NIC in
standalone, stacking, or VLT mode for LACP-based NIC teaming, server-facing ports are automatically
configured as part of dynamic LAGs. The LAG range 1 to 127 is reserved for server-facing LAGs.
After the Aggregator receives LACPDU from server-facing ports, the information embedded in the
LACPDU (remote-system ID and port key) is used to form a server-facing LAG. The LAG/port-channel
number is assigned based on the first available number in the range from 1 to 127. For each unique
remote system-id and port-key combination, a new LAG is formed and the port automatically becomes a
member of the LAG.
All ports with the same combination of system ID and port key automatically become members of the
same LAG. Ports are automatically removed from the LAG if the NIC teaming configuration on a server-
facing port changes or if the port goes operationally down. Also, a server-facing LAG is removed when
the last port member is removed from the LAG.
The benefit of supporting a dynamic LAG is that the Aggregator's server-facing ports can toggle between
participating in the LAG or acting as individual ports based on the dynamic information exchanged with a
server NIC. LACP supports the exchange of messages on a link to allow their LACP instances to:
• Reach agreement on the identity of the LAG to which the link belongs.
• Attach the link to that LAG.
• Enable the transmission and reception functions in an orderly manner.
• Detach the link from the LAG if one of the partner stops responding.
LACP Modes
The Aggregator supports only LACP active mode as the default mode of operation. In active mode, a port
interface is considered to be not part of a LAG but rather in an active negotiating state.
A port in active mode automatically initiates negotiations with other ports by sending LACP packets. If
you configure server-facing ports for LACP-based NIC teaming, LACP negotiations take place to
aggregate the port in a dynamic LAG. If you do not configure server-facing ports for LACP-based NIC
teaming, a port is treated as an individual port in active negotiating state.
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Link Aggregation