nstat

View network statistics since last time nstat was run

$ nstat

$ nstat -a

$ nstat -h

nstat [options]

nstat displays network statistics from /proc/net/netstat and /proc/net/snmp, showing IP, ICMP, TCP, and UDP counters. By default, it shows only the changes since the last time nstat was run, making it useful for monitoring network activity over time.
The tool maintains a history file (~/.nstat.u) to track previous values. Running nstat shows the difference (increment) since the last run, then updates the history. Use -s to view without updating.
Statistics include packet counts, errors, retransmissions, and various protocol-specific metrics useful for network troubleshooting.

-a, --ignore

Show absolute values (all-time statistics) instead of incremental

Don't display header or output (just reset counters)

Reset history

Don't update history (show stats without resetting)

Show entries with zero values

Output in JSON format

Display help information

Incremental mode depends on the history file; first run shows all zeros. The -a flag shows totals since boot, ignoring history. Part of the iproute2 package.

ss(8), ip(8), netstat(8), sar(1)