Linux 搭建PPTP Server连接超过100个后，就再无法拨号成功了。
查看log 发现有以下信息：
2 | Nov 20 11:17:13 pptpd[21132]: CTRL: Received PPTP Control Message (type: 5) |
3 | Nov 20 11:17:13 pptpd[21132]: CTRL: Made a ECHO RPLY packet |
4 | Nov 20 11:17:13 pptpd[21132]: CTRL: I wrote 20 bytes to the client. |
5 | Nov 20 11:17:13 pptpd[21132]: CTRL: Sent packet to client |
4 | limits the number of client connections that may be accepted. |
5 | If pptpd is allocating IP addresses (e.g. delegate is not used) |
6 | then the number of connections is also limited by the remoteip |
7 | option. The default is 100. |
PPTP Server 最大连接数，是connections和地址池数量一起控制的，connections默认是100，导致无法连接更多。
如果希望最大连接1000条，可以在pptpd.conf中添加一行配置（地址池要有1000个地址）：
connections 1000