I'm running Centos 6.4, and I got pptpd working, for the most part. I am connecting from a Windows 7 machine, and once connected I can access all the intranet sites as well as sites that are already open, or have been opened recently, like google.com. What I can't access is new sites (like when I tried connecting to serverfault), so I think it is related to DNS. I have been able to access a few sites by their IP, but most seem to redirect the IP to the domain name, which then fails. From cmd, I can ping new sites, so it is resolving DNS there. Is the command line resolving DNS through the LAN while Chrome tries to do it through the VPN? I've searched many forums and blogs looking for an answer, but still haven't found anything that fixed it for me. I have tried disabling selinux and also iptables (both non-persistently), just to reduce the number of variables.
Possibly related: these lines keep showing up in /var/log/messages
GRE: read(fd=7,buffer=6097c0,len=8260) from network failed: status = -1 error = Protocol not available CTRL: GRE read or PTY write failed (gre,pty)=(7,6)
Here are some config files that might be relevant in determining what is wrong:
ppp /usr/sbin/pppd option /etc/ppp/options.pptpd logwtmp remoteip 192.168.16.36-49 #these are reserved, not used by dhcp localip 192.168.16.35
name pptpd refuse-pap refuse-chap refuse-mschap require-mschap-v2 require-mppe-128 ms-dns 192.168.16.2 #domain controller, dns server ms-wins 192.168.16.2 proxyarp lock nobsdcomp novj novjccomp nologfd auth