使用nload工具可以实时查看网络流量 nload -u M -m

官网及下载

http://www.roland-riegel.de/nload/index.html 
http://www.roland-riegel.de/nload/nload-0.7.2.tar.gz

http://dl.wdlinux.cn:5180/soft/nload-0.7.2.tar.gz

安装

wget http://www.roland-riegel.de/nload/nload-0.7.2.tar.gz
tar zxvf nload-0.7.2.tar.gz
cd nload-0.7.2
./configure;make;make install 

使用
直接用nload回车即可,也可以指定网卡,如nload eth1
还可以指定是以K或M来显示流量,如nload -u M显示的流量是以MB为单位的

看看还有哪些参数或选项

 Command line syntax:
nload [options] [devices]
nload --help|-h
Options:
-a period       Sets the length in seconds of the time window for average
                calculation.
                Default is 300.
-i max_scaling  Specifies the 100% mark in kBit/s of the graph indicating the
                incoming bandwidth usage. Ignored if max_scaling is 0 or the
                switch -m is given.
                Default is 10240.
-m              Show multiple devices at a time; no traffic graphs.
-o max_scaling  Same as -i but for the graph indicating the outgoing bandwidth
                usage.
                Default is 10240.
-t interval     Determines the refresh interval of the display in milliseconds.
                Default is 500.
-u h|b|k|m|g    Sets the type of unit used for the display of traffic numbers.
   H|B|K|M|G    h: auto, b: Bit/s, k: kBit/s, m: MBit/s etc.
                H: auto, B: Byte/s, K: kByte/s, M: MByte/s etc.
                Default is h.
-U h|b|k|m|g    Same as -u, but for a total amount of data (without "/s").
   H|B|K|M|G    Default is H.
devices         Network devices to use.
                Default is to use all auto-detected devices.
--help
-h              Print this help.
example: nload -t 200 -i 1024 -o 128 -U M