User guide

Virtual Connect networks 101
Configuration changes can be made without having to enable Throughput Statistics. Applying configuration
changes when Throughput statistics is enabled clears all existing samples.
Some conditions can clear existing Throughput Statistics:
• Disabling the collection of Throughput Statistics clears all existing samples.
• Changing the sampling rate clears all existing samples.
• Power cycling a VC-Enet module clears all Throughput Statistics samples for that module.
Collected samples are available for analysis on the Throughput Statistics screen (on page 223), accessible
by selecting Throughput Statistics from the Tools pull-down menu.
The following table describes the available actions for changing Throughput Statistics settings.
Task Action
Enable/disable
Select (enable) or clear (disable) the Enable Throughput Statistics checkbox.
Change sampling rate
Select a sampling rate from the Configuration list. Supported sampling rates
include:
•
Sample rate of 1 minute, collecting up to 5 hours of samples.
•
Sample rate of 2 minutes, collecting up to 10 hours of samples.
•
Sample rate of 3 minutes, collecting up to 15 hours of samples.
•
Sample rate of 4 minutes, collecting up to 20 hours of samples.
•
Sample rate of 5 minutes, collecting up to 25 hours of samples.
•
Sample rate of 1 hour, collecting up to 12.5 days of samples.
LACP timer configuration
Virtual Connect provides two options for configuring uplink redundancy (Auto and Failover). When the
connection mode is set to "Auto", VC uses Link Aggregation Control Protocol to aggregate uplink ports from
a Network or Shared Uplink Set into Link Aggregation Groups. As part of the LACP negotiation to form a
LAG, the remote switch sends a request for the frequency of the control packets (LACPDU). This frequency can
be "short" or "long." Short is every 1 second with a 3 second timeout. Long is every 30 seconds with a 90
second timeout.
Prior to VC 4.01 this setting defaulted to short. Starting with VC v4.01 this setting can be set to short or long.
The domain-wide setting can be changed on the Ethernet Settings (Advanced Settings) screen ("Ethernet
Networks (Advanced Settings)" on page 96). Additionally, each Network or Shared Uplink Set also has a
LACP timer setting. There are three possible values: Domain-Default, Short, or Long. The domain default
option sets the LACP timer to the domain-wide default value that is specified on the Advanced Ethernet
Settings screen.
This setting specifies the domain-wide default LACP timer. VCM uses this value to set the duration of the LACP
timeout and to request the rate at which LACP control packets are to be received on LACP-supported
interfaces. Changes to the domain-wide setting are immediately applied to all existing networks and shared
uplink sets.
Using the "long" setting can help prevent loss of LAGs while performing in-service upgrades on upstream
switch firmware.
Quality of Service
QoS is used to provide different priorities for designated networking traffic flows and guarantee a certain
level of performance through resource reservation. QoS is important for the following reasons: