pptp

Linux命令行拨pptpd

Debian/Ubuntu PPTP VPN 安装笔记: http://wangyan.org/blog/debian-pptp-vpn.html
PPTP/L2TP + FreeRADIUS + MySQL 安装与配置: http://wangyan.org/blog/freeradius-pptp-l2tp-html.html

Linux命令行拨pptpd

# 设置vpn客户端
sudo pptpsetup --create myVPN --server x.x.x.x --username vpn --password 123456 --encrypt

# 拨号
sudo pppd call myVPN updetach

# 调试
sudo pppd call myVPN debug dump logfd 2 updetach

LCP: timeout sending Config-Requests错误处理

参考：http://askubuntu.com/questions/269399/pptp-vpn-cant-connect

Aug  8 02:59:17 localhost pppd[8659]: LCP: timeout sending Config-Requests

Edit /etc/ppp/options, enable option silent, then problem solved.

# With this option, pppd will not transmit LCP packets to initiate a
# connection until a valid LCP packet is received from the peer (as for
# the "passive" option with old versions of pppd).
silent

PTY read or GRE write failed

Aug  8 02:59:17 localhost pptpd[8658]: GRE: read(fd=6,buffer=611860,len=8196) from PTY failed: status = -1 error = Input/output error, usually caused by unexpected termination of pppd, check option syntax and pppd logs
Aug  8 02:59:17 localhost pptpd[8658]: CTRL: PTY read or GRE write failed (pty,gre)=(6,7)

Aug  8 02:27:03 UDesktop pptpd[12957]: GRE: Bad checksum from pppd.