OP – FWIW, when I’ve used PPTP connection to some commercial providers (including PureVPN) with OpenWrt/LEDE, it wasn’t reliable enough to keep using it. It would work wonders for up to 8 hours on boot and then it would stall. I couldn’t figure out the way to troubleshoot it, so it wouldn’t stall from time to time so I just switched to OpenVPN (it’s slower but harder to crack).
BTW, here’s what’s required for PureVPN PPTP connection to work with a typical router setup on LEDE:
cat << 'EOF' > /etc/ppp/options.pptp
noipdefault
noauth
nobsdcomp
nodeflate
idle 0
maxfail 0
refuse-pap
refuse-eap
refuse-chap
refuse-mschap
EOF
uci set network.vpnc=interface
uci set network.vpnc.peerdns=0
uci set network.vpnc.dns=192.168.1.1
uci set network.vpnc.password=********
uci set network.vpnc.proto=pptp
uci set network.vpnc.server=cav.pointtoserver.com
uci set network.vpnc.username=*******
uci set network.vpnc.enabled=1
uci set network.vpnc.pppd_options=debug
uci set network.vpnc.pptpd_options=debug
uci add firewall zone
uci set firewall.@zone[-1]=zone
uci set firewall.@zone[-1].name=vpnc_fw
uci set firewall.@zone[-1].network=vpnc
uci set firewall.@zone[-1].input=REJECT
uci set firewall.@zone[-1].output=ACCEPT
uci set firewall.@zone[-1].forward=REJECT
uci set firewall.@zone[-1].masq=1
uci set firewall.@zone[-1].mtu_fix=1
uci add firewall forwarding
uci set firewall.@forwarding[-1]=forwarding
uci set firewall.@forwarding[-1].src=lan
uci set firewall.@forwarding[-1].dest=vpnc_fw
uci add firewall forwarding
uci set firewall.@forwarding[-1]=forwarding
uci set firewall.@forwarding[-1].src=guest
uci set firewall.@forwarding[-1].dest=vpnc_fw
uci commit