Administrator Guide

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 the LACP link fallback member
By default, the lacp link-fallback member-independent port-channel 128 command is enabled
on the Standalone mode. This command is not available in the VLT mode. To disable the
LACP link
fallback member
, use the no lacp link-fallback member-independent port-channel 128
command.
The following log message appears when LACP link fallback is enabled:
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
Link Aggregation 537