---

n.razhev@n-razhev ~ % >....                                                                                                                                                                                       
    netstat -an -p tcp | awk '/194[.]186[.]63[.]/ && /ESTABLISHED/ {print}'
    /usr/bin/nc -4 -n -z -v -G 6 -w 6 10.12.165.142 8443
    /usr/bin/dig @172.21.0.1 jss.corp.mail.ru A +time=4 +tries=1 +notcp +ignore +noall +comments +answer
    netstat -an -p tcp | awk '/194[.]186[.]63[.]/ && /ESTABLISHED/ {print}'
  }

  tb_routes || exit 1
  tb_initial_flow=$(tb_flow)
  [ -n "$tb_initial_flow" ] || { echo 'Stop: no corporate TCP connection.'; exit 1; }
  sudo -v || exit 1

  echo 'BASELINE: TSO enabled'
  tb_probe
  tb_routes || exit 1

  tb_restore() {
    trap - EXIT
    echo 'Restoring original TSO setting:'
    if sudo -n /sbin/ifconfig bridge0 tso; then
      tb_restored=$(/sbin/ifconfig bridge0 | awk '/options=/{print}')
      printf '%s\n' "$tb_restored"
      [ "$tb_restored" = "$tb_original" ] || echo 'WARNING: restored flags differ from the original.'
    else
      echo 'Restore failed. Run: sudo /sbin/ifconfig bridge0 tso'
    fi
  }
  trap tb_restore EXIT
  trap 'exit 130' HUP INT TERM

  sudo -n /sbin/ifconfig bridge0 -tso || exit 1
  tb_disabled=$(/sbin/ifconfig bridge0 | awk '/options=/{print}')
  printf '%s\n' "$tb_disabled"
  case "$tb_disabled" in
    *'options=3<RXCSUM,TXCSUM>'*) ;;
    *) echo 'Stop: expected TSO-only change did not take effect.'; exit 1 ;;
  esac

  echo 'TSO disabled temporarily; waiting 10 seconds for queued traffic.'
  sleep 10
  tb_routes || exit 1
  echo 'COMPARISON: TSO disabled'
  tb_probe
  tb_routes || exit 1

  if [ "$(tb_flow)" = "$tb_initial_flow" ]; then
    echo 'Corporate TCP connection is unchanged.'
  else
    echo 'Corporate TCP connection changed; comparison is inconclusive.'
  fi
)
BASELINE: TSO enabled
Tue Oct  6 12:49:24 UTC 2026
tcp4       0 126100  192.168.77.2.58316     194.186.63.23.443      ESTABLISHED
nc: connectx to 10.12.165.142 port 8443 (tcp) failed: Operation timed out

; <<>> DiG 9.10.6 <<>> @172.21.0.1 jss.corp.mail.ru A +time=4 +tries=1 +notcp +ignore +noall +comments +answer
; (1 server found)
;; global options: +cmd
;; connection timed out; no servers could be reached
tcp4       0 129996  192.168.77.2.58316     194.186.63.23.443      ESTABLISHED
ifconfig: -tso: Operation not supported on socket
Restoring original TSO setting:
ifconfig: tso: Operation not supported on socket
Restore failed. Run: sudo /sbin/ifconfig bridge0 tso

Saving session...
...saving history...truncating history files...
...completed.