通过编写脚本代码查看统计服务器网络流量。
步骤很简单，在/etc/ppp/ip-up文件最下边添加下边的脚本：
echo "****************************************************" >> /var/log/VPN-${1}.log
echo "username: $PEERNAME" >> /var/log/VPN-${1}.log
echo "clientIP: $6" >> /var/log/VPN-${1}.log
echo "device: $1" >> /var/log/VPN-${1}.log
echo "vpnIP: $4" >> /var/log/VPN-${1}.log
echo "assignIP: $5" >> /var/log/VPN-${1}.log
echo "logintime: `date -d today +%F_%T`" >> /var/log/VPN-${1}.log在/etc/ppp/ip-down文件最下边添加下边的脚本：
echo "downtime: `date -d today +%F_%T`" >> /var/log/VPN-${1}.log
echo "bytes sent: $BYTES_SENT B" >> /var/log/VPN-${1}.log
echo "bytes received: $BYTES_RCVD B" >> /var/log/VPN-${1}.log
sum_bytes=$(($BYTES_SENT+$BYTES_RCVD))
sum=`echo "scale=2;$sum_bytes/1024/1024"|bc`
echo "bytes sum: $sum MB" >> /var/log/VPN-${1}.log
ave=`echo "scale=2;$sum_bytes/1024/$CONNECT_TIME"|bc`
echo "average speed: $ave KB/s" >> /var/log/VPN-${1}.log
echo "connect time: $CONNECT_TIME S" >> /var/log/VPN-${1}.log
echo "****************************************************" >> /var/log/VPN-${1}.log注意这个代码为了计算平局网速用到了dc工具，可能需要提前安装：
sudo apt install bc然后就能在/var/log/VPN-ppp0.log中看到vpn连接记录类似这样：
****************************************************
username: XXX
clientIP: XXX.XXX.XXX.XXX
device: ppp0
vpnIP: 172.16.0.1
assignIP: 172.16.0.10
logintime: 2018-06-10_17:11:20
downtime: 2018-06-10_17:11:21
bytes sent: 3272 B
bytes received: 3626 B
bytes sum: 0 MB
average speed: 6.73 KB/s
connect time: 1 S
****************************************************如果有多个用户同时连接，那么可能会生成多个log文件，通过ppp*这个星号数字作区分。
侵删转自：矛盾体
