1、sar -n DEV 2 0
sar命令详解：
-n { DEV | EDEV | NFS | NFSD | SOCK | ALL }
Report network statistics.
With the DEV keyword, statistics from the network devices are reported. The
following values are displayed:
IFACE
Name of the network interface for which statistics are reported.
rxpck/s
Total number of packets received per second.
txpck/s
Total number of packets transmitted per second.
rxbyt/s
Total number of bytes received per second.
txbyt/s
Total number of bytes transmitted per second.
rxcmp/s
Number of compressed packets received per second (for cslip etc.).
txcmp/s
Number of compressed packets transmitted per second.
rxmcst/s
Number of multicast packets received per second.
2、watch ifconfig 网卡