Arch Linux

panda fuligineux

Member

Registered: 2017-12-15

Posts: 5

Connexion to a VPN using PPP and MPPE

Hello everyone,

I would like to connect my school's VPN using PPP and MPPE using NetworkManager. So I installed the package for that (networkmanager-pptp) and I followed the instruction of my school to connect to the VPN using linux and network manager.
Unfortunately, even though it seems I can connect (don't have any error message, ip addr show tells me that I have a new ppp0 interface), I have no internet connection. I can't even ping the IP of my school's VPN.

There is something on the wiki which seems related to my problem : https://wiki.archlinux.org/index.php/Ne … PTP_tunnel

"It is due to lack of MPPE (Microsoft Point-to-Point Encryption) support in stock Arch pppd. It is recommended to first try with the stock Arch ppp as it may work as intended. "

I've checked and the package ppp is installed (but it does not work)

"To solve the problem it should be sufficient to install the ppp-mppe" ---> but this package does not exist on the AUR... Is it safe to install an old version (not updated since 3 years !) ?

Another link says "WPA2-Enterprise wireless networks demanding MSCHAPv2 type-2 authentication with PEAP sometimes require pptpclient in addition to the stock ppp package." I have also installed the package "pptpclient" but nothing changes.

Do you have any idea of what can I do ?

I hope I was precise enough. I'm really new to arch linux and I don't have a lot of knowledge in informatics, so don't hesitate to be precise

Have a good day,
PF.

Achelous

Member

Registered: 2017-12-15

Posts: 9

Re: Connexion to a VPN using PPP and MPPE

I'm guessing that it's trying to put all your internet traffic through the VPN, rather than just the desired subnet(s).

Please could you give the output of "ip route", before and after starting a VPN connection?

panda fuligineux

Member

Registered: 2017-12-15

Posts: 5

Re: Connexion to a VPN using PPP and MPPE

Before VPN connection, I use WiFi :

default via 192.168.1.254 dev wlp3s0 proto dhcp metric 600
192.168.1.0/24 dev wlp3s0 proto kernel scope link src 192.168.1.231 metric 600

Now, if I activate the VPN connection :

default via 192.168.1.254 dev wlp3s0 proto dhcp metric 600
192.168.1.0/24 dev wlp3s0 proto kernel scope link src 192.168.1.231 metric 600
192.168.1.254 dev wlp3s0 proto static scope link metric 600
XXX.YY.68.242 dev ppp0 proto kernel scope link src ZZZ.UU.246.93 metric 50
XXX.YY.68.242 via 192.168.1.254 dev wlp3s0 proto static metric 600

hfenigma

Member

Registered: 2017-06-29

Posts: 32

Re: Connexion to a VPN using PPP and MPPE

The wiki page need to be updated, you don't have to install the ppp-mppe package now, just load the ppp_mppe kernel module.

Achelous

Member

Registered: 2017-12-15

Posts: 9

Re: Connexion to a VPN using PPP and MPPE

Thanks. Based on that, it looks like normal internet traffic should still be going over WiFi.

Are you sure it's not just a DNS issue? Does "ping 216.58.210.46" work?

progandy

Member

Registered: 2012-05-17

Posts: 5,311

Re: Connexion to a VPN using PPP and MPPE

There is something on the wiki which seems related to my problem : https://wiki.archlinux.org/index.php/Ne … PTP_tunnel

"It is due to lack of MPPE (Microsoft Point-to-Point Encryption) support in stock Arch pppd. It is recommended to first try with the stock Arch ppp as it may work as intended. "

I've checked and the package ppp is installed (but it does not work)

"To solve the problem it should be sufficient to install the ppp-mppe" ---> but this package does not exist on the AUR... Is it safe to install an old version (not updated since 3 years !) ?

MPPE is part of the linux kernel (since 3.something or so?) and should work with the stock pppd since version 2.4.2
https://ppp.samba.org/ftp/unpacked/ppp/README

Last edited by progandy (2017-12-16 13:07:13)

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panda fuligineux

Member

Registered: 2017-12-15

Posts: 5

Re: Connexion to a VPN using PPP and MPPE

OK... So I verified and this module is loaded. In doubt I loaded it with "modprobe ppp_mppe" and tried. It still does not work.

I can't ping anything (I have no responses)

panda fuligineux

Member

Registered: 2017-12-15

Posts: 5

Re: Connexion to a VPN using PPP and MPPE

(up) Any other idea ?

I verified with my old computer (debian) which can connect to this VPN and I do have the good options set so... I really don't know what to do...