I've noticed recently that PPTPD server, worked perfectly fine on LEDE 17.01.1, can't be connected in LEDE 17.01.2. After small research I've also found out that it become unconnectable even on 17.01.1 after > opkg upgrade firewall
In both case similar error raised in system log:
GRE: xmit failed from decaps_hdlc: Operation not permitted
I know and understand that PPTP is less secure than L2TP+IpSec or openVPN, but in my case PPTPD is still much more comfortable for various devices (Windows, Linux, Android, iOS, MacOS), plus there is no really secret/sensitive data inside the channel. So at the moment I don't have any alternative for PPTPD.
Can you please help me, how can I upgrage firewall and keep PPTPD operational?