Jan 17 04:52:57 cloudlix pppd[18873]: Connect: ppp0 <--> /dev/pts/1
Jan 17 04:53:27 cloudlix pppd[18873]: LCP: timeout sending Config-Requests
Jan 17 04:53:27 cloudlix pppd[18873]: Connection terminated.
Jan 17 04:53:27 cloudlix pppd[18873]: Modem hangup
Jan 17 04:53:27 cloudlix pppd[18873]: Exit.
This error means you local ot network firewall blocks GRE packets, so if you are using Fedora just do this:
sudo firewall-cmd --permanent --direct --add-rule ipv4 filter INPUT 0 -p gre -j ACCEPT
sudo firewall-cmd --permanent --direct --add-rule ipv6 filter INPUT 0 -p gre -j ACCEPT (if you are using IPV6)
sudo firewall-cmd --reload