White Papers

Table Of Contents
0 packets, 0 bytes
0 64-byte pkts, 0 over 64-byte pkts, 0 over 127-byte pkts
0 over 255-byte pkts, 0 over 511-byte pkts, 0 over 1023-byte pkts
0 Multicasts, 0 Broadcasts
0 runts, 0 giants, 0 throttles
0 CRC, 0 overrun, 0 discarded
Output Statistics:
0 packets, 0 bytes, 0 underruns
0 64-byte pkts, 0 over 64-byte pkts, 0 over 127-byte pkts
0 over 255-byte pkts, 0 over 511-byte pkts, 0 over 1023-byte pkts
0 Multicasts, 0 Broadcasts, 0 Unicasts
0 throttles, 0 discarded, 0 collisions, 0 wreddrops
Rate info (interval 299 seconds):
Input 00.00 Mbits/sec, 0 packets/sec, 0.00% of line-rate
Output 00.00 Mbits/sec, 0 packets/sec, 0.00% of line-rate
Time since last interface status change: 05:22:28
Optimizing Traffic Disruption Over LAG Interfaces On
IOA Switches in VLT Mode
When you use the write memory command while an Aggregator operates in VLT mode, the VLT LAG configurations are saved
in nonvolatile storage (NVS).
By restoring the settings saved in NVS, the VLT ports come up quicker on the primary VLT node and traffic disruption is
reduced. The delay in restoring the VLT LAG parameters is reduced (90 seconds by default) on the secondary VLT peer node
before it becomes operational. This makes sure that the configuration settings of the primary VLT node are synchronized with
the secondary VLT peer node before the secondary VLT mode is up. The traffic outage is less than 200 millisconds during the
restart or switchover of the VLT peer nodes from primary to secondary.
Preserving LAG and Port Channel Settings in
Nonvolatile Storage
Use the write memory command on an I/O Aggregator, which operates in either standalone or PMUX modes, to save the
LAG port channel configuration parameters. This behavior enables the port channels to be brought up because the configured
interface attributes are available in the system database during the booting of the device. With the reduction in time for the port
channels to become active after the switch is booted, the loss in the number of packets that are serviced by these interfaces is
minimized.
Enabling LACP link-fallback
By default, the lacp link-fallback member-independent port-channel 128 command is enabled on the
Standalone, VLT, and Stacking mode. To disable the LACP linkfallback, use the no lacp link-fallback member-
independent port-channel 128 command.
The following log message is displayed when LACP link fallback is elected:
Feb 26 15:53:32: %STKUNIT0-M:CP IFMGR-5-NO_LACP_PDU_RECEIVED_FROM_PEER: Connectivity to
PEER is restricted because LACP PDU's are not received. Verify the LACP configurations
on PEER to bring up the Uplink LAG to attain better bandwidth
May 12 16:31:22: %STKUNIT1-M:CP %IFMGR-5-LACP_LINK_FALLBACK_ELECTED: Te 1/11 : Elected
LACP Fallback Link
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Link Aggregation