How to measure network traffic to/from a Vertica cluster

Hi Dieter,
To monitor the network bandwidth usage history, check the outgoing and incoming KB per second in the NETWORK_USAGE table.

select
    RIGHT(node_name,4) as node,
    LEFT(time_slice(start_time, 1,'hour')::varchar,16) as hour_slice,
    round(avg(tx_kbytes_per_sec)) as avg_tx_KB_sec,
    round(max(tx_kbytes_per_sec)) as max_tx_KB_sec,
    round(avg(rx_kbytes_per_sec)) as avg_rx_KB_sec,
    round(max(rx_kbytes_per_sec)) as max_rx_KB_sec
from NETWORK_USAGE
where
      ( NOW() - start_time) < '6 hour'
group by 1,2
order by 2 desc,1;

To validate if LAN conf. minimum requirements are met on target env. use vnetperf

Thank you Moshe for this suggestion.
Would this query report the complete network traffic in/out per node? The task I am trying to solve to measure network traffic into/out the cluster (traffic on the external network). From the doc for network_usage it is not clear if this is for traffic on the internal or the external network. The doc says:
NETWORK_USAGE
Provides network bandwidth usage history on the system. This is useful for determining if Vertica is using a large percentage of its available network bandwidth.
This could be understood as measuring traffic on the internal network.
Would we have any chance to verify what network_usage reports?
Thank you
Dieter