PPTP VPN connecting issue

horizn · 10-12-2021, 02:46 PM

I got into weird issue with PPTP VPN. For some reason the same configuration works fine (I am able to connect) on Ubuntu 20.04 but it doesn't work in Debian 10 or 11. On Debian in the logs I am getting:

Code:

Oct 12 17:44:51 x pppd[567]: Connect: ppp0 <--> /dev/pts/1
Oct 12 17:44:51 x systemd-udevd[569]: ethtool: autonegotiation is unset or enabled, the speed and duplex are not writable.
Oct 12 17:44:51 x pptp[570]: anon log[main:pptp.c:353]: The synchronous pptp option is NOT activated
Oct 12 17:44:52 x pptp[579]: anon log[ctrlp_rep:pptp_ctrl.c:259]: Sent control packet type is 1 'Start-Control-Connection-Request'
Oct 12 17:44:52 x pptp[579]: anon log[ctrlp_disp:pptp_ctrl.c:781]: Received Start Control Connection Reply
Oct 12 17:44:52 x pptp[579]: anon log[ctrlp_disp:pptp_ctrl.c:815]: Client connection established.
Oct 12 17:44:52 x pppd[567]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x1346f064> <pcomp> <accomp>]
Oct 12 17:44:53 x pptp[579]: anon log[ctrlp_rep:pptp_ctrl.c:259]: Sent control packet type is 7 'Outgoing-Call-Request'
Oct 12 17:44:53 x pptp[579]: anon log[ctrlp_disp:pptp_ctrl.c:900]: Received Outgoing Call Reply.
Oct 12 17:44:53 x pptp[579]: anon log[ctrlp_disp:pptp_ctrl.c:939]: Outgoing call established (call ID 35522, peer's call ID 26496).
Oct 12 17:44:55 x pppd[567]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x1346f064> <pcomp> <accomp>]
Oct 12 17:44:58 x pppd[567]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x1346f064> <pcomp> <accomp>]
Oct 12 17:45:01 x pppd[567]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x1346f064> <pcomp> <accomp>]
Oct 12 17:45:04 x pppd[567]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x1346f064> <pcomp> <accomp>]
Oct 12 17:45:07 x pppd[567]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x1346f064> <pcomp> <accomp>]
Oct 12 17:45:10 x pppd[567]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x1346f064> <pcomp> <accomp>]
Oct 12 17:45:13 x pppd[567]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x1346f064> <pcomp> <accomp>]
Oct 12 17:45:16 x pppd[567]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x1346f064> <pcomp> <accomp>]
Oct 12 17:45:19 x pppd[567]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x1346f064> <pcomp> <accomp>]
Oct 12 17:45:22 x pppd[567]: LCP: timeout sending Config-Requests
Oct 12 17:45:22 x pppd[567]: Connection terminated.
Oct 12 17:45:22 x pppd[567]: Modem hangup

it is not a matter of loading

Code:

nf_conntrack_pptp

or

Code:

nf_conntrack_proto_gre kernel modules

here is the config:

Code:

pty "pptp 1.2.3.4 --nolaunchpppd --debug"
name login
password password
remotename PPTP
#require-mppe-128
require-mschap-v2
refuse-eap
refuse-pap
refuse-chap
refuse-mschap
noauth
debug
persist
maxfail 0
defaultroute
replacedefaultroute
usepeerdns

any ideas?

Turbocapitalist · 10-13-2021, 08:20 AM

The PPTP VPNs are obsolete.

If you have the possibility IKE, IPSec, OpenVPN, WireGuard, or even an ad-hoc SSH VPN would be sound choices. Can you use one of those instead?

uteck · 10-13-2021, 08:52 AM

I found on a search, to add the "silent" option to your config, so it will wait for a packet from the server.
But PPTP is a dead technology, and you should replace it with something that is secure. Tailscale lets you easily setup wireguard on nearly all OS's.

horizn · 10-13-2021, 09:35 AM

Quote:

Originally Posted by uteck

I found on a search, to add the "silent" option to your config, so it will wait for a packet from the server.
But PPTP is a dead technology, and you should replace it with something that is secure. Tailscale lets you easily setup wireguard on nearly all OS's.

So how this can help to solve my issue? I know it is obsolete but it is not me who managing this.