PPTP in VM "system lacks PPP kernel support" Kernel 2.6.32-4-pve

pkhooper

New Member
Aug 3, 2010
6
0
1
Hello,

I am trying to start up a pptp client session in a VM.

I have followed the instructions in the OpenVZ Wiki - http://wiki.openvz.org/Ppp_in_VE

I have tried this in both a Debian v6 and Debian v5 VM.

In Debian 6, I get the following error when I try to run pppd. (/usr/sbin/pppd)

Code:
Couldn't open the /dev/ppp device: Operation not permitted
/usr/sbin/pppd: Sorry - this system lacks PPP kernel support

In Debian 5, I get the following error

Code:
/usr/sbin/pppd: This system lacks kernel support for PPP.  This could be because
the PPP kernel module could not be loaded, or because PPP was not
included in the kernel configuration.  If PPP was included as a
module, try `/sbin/modprobe -v ppp'.  If that fails, check that
ppp.o exists in /lib/modules/`uname -r`/net.
See README.linux file in the ppp distribution for more details.

I am able to run a PPTP Session in the Host running the following version.

Code:
pve01:/# pveversion --verbose
pve-manager: 1.6-2 (pve-manager/1.6/5087)
running kernel: 2.6.32-4-pve
proxmox-ve-2.6.32: 1.6-19
pve-kernel-2.6.32-4-pve: 2.6.32-19
pve-kernel-2.6.18-2-pve: 2.6.18-5
qemu-server: 1.1-18
pve-firmware: 1.0-8
libpve-storage-perl: 1.0-14
vncterm: 0.9-2
vzctl: 3.0.24-1pve4
vzdump: 1.2-7
vzprocps: 2.0.11-1dso2
vzquota: 3.0.11-1
pve-qemu-kvm: 0.12.5-1
ksm-control-daemon: 1.0-4

PPTP Interface up on the host to show it is working.

Code:
ppp0      Link encap:Point-to-Point Protocol
          inet addr:10.131.1.107  P-t-P:10.131.1.155  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1396  Metric:1
          RX packets:305 errors:0 dropped:0 overruns:0 frame:0
          TX packets:39 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3
          RX bytes:23940 (23.3 KiB)  TX bytes:2684 (2.6 KiB)

Given I can run a PPTP session from the Host, why am I getting "Kernel Does Not Support PPP" from the VMs?

Below is the configuration of interest for the VMs, so you can see network and device information.

Code:
# CPU fair sheduler parameter
CPUUNITS="1000"
CPUS="1"
VE_ROOT="/var/lib/vz/root/$VEID"
VE_PRIVATE="/var/lib/vz/private/$VEID"
OSTEMPLATE="debian-6.0-standard_6.0-1_i386"
ORIGIN_SAMPLE="pve.auto"
HOSTNAME="wdnms-p01"
NAMESERVER="192.168.0.7"
SEARCHDOMAIN="combinedcommunications.com.au"
NETIF="ifname=eth0,mac=52:66:66:3B:E0:EC,host_ifname=veth107.0,host_mac=00:18:51:02:AA:7F"
IP_ADDRESS="192.168.180.247"
DEVICES="c:10:200:rw "
FEATURES="ppp:on "
CAPABILITY="NET_ADMIN:on "
DEVNODES="net/tun:rw "

Any help will be greatly appreciated.

Regards,
Patrick.
 
If you follow the howto (http://wiki.openvz.org/Ppp_in_VE) you will see that you need either a 2.6.27 or a 2.6.18 based kernel - 2.6.32 seems not supported.

I played a bit with our 2.6.18er, but I am not a ppp expert. Also see the howto in the bugzilla link on the bottom of the wiki page.

I suggest you try our 2.6.18er, but this feature is marked as experimental. So I would not run it in production machines, maybe you should use KVM guests for this.
 
Martin,

Thank you for your response.

In (http://wiki.openvz.org/Ppp_in_VE) it says kernel 2.6.27 or later, so 2.6.32 is later and should be supported.

It is also necessary to run one of these 2 kernels :
2.6.27 briullov.1 or later
rhel5 064.4 or later

Working through other posts, the problem in the older kernels was that ppp was not supported in the host, however, I am able to run the pptp session on the host, but not on the VE.

Code:
Linux pve01 2.6.32-4-pve #1 SMP Mon Sep 20 11:36:51 CEST 2010 x86_64

pve01:~# lsmod | grep ppp
ppp_mppe                5128  0
ppp_deflate             3410  0
zlib_deflate           17730  1 ppp_deflate
ppp_async               6245  0
ppp_generic            19051  3 ppp_mppe,ppp_deflate,ppp_async
slhc                    3987  1 ppp_generic
crc_ccitt               1323  1 ppp_async
pve01:~#

There seems to be something wrong with the way that the kernel services are exposed in the VE.

If you look at this post you can see other people have this feature working without issue.

http://serverfault.com/questions/184607/good-easy-free-vpn-solution-you-can-use-with-openvz

http://www.webhostingtalk.com/archive/index.php/t-956715.html

So from what I can see other people have ppp working on OpenVZ, but I can't get it to work on Proxmox.

Regards,
Patrick.
 
Martin,

Thank you for your response.

In (http://wiki.openvz.org/Ppp_in_VE) it says kernel 2.6.27 or later, so 2.6.32 is later and should be supported.

I read this different. 2.6.27 briullov.1 or later means just later 2.6.27 kernels. this does no mean 2.6.32 is supported.



Working through other posts, the problem in the older kernels was that ppp was not supported in the host, however, I am able to run the pptp session on the host, but not on the VE.

Code:
Linux pve01 2.6.32-4-pve #1 SMP Mon Sep 20 11:36:51 CEST 2010 x86_64

pve01:~# lsmod | grep ppp
ppp_mppe                5128  0
ppp_deflate             3410  0
zlib_deflate           17730  1 ppp_deflate
ppp_async               6245  0
ppp_generic            19051  3 ppp_mppe,ppp_deflate,ppp_async
slhc                    3987  1 ppp_generic
crc_ccitt               1323  1 ppp_async
pve01:~#

There seems to be something wrong with the way that the kernel services are exposed in the VE.

If you look at this post you can see other people have this feature working without issue.
I cannot find a post from anyone running it on a 2.6.32 kernel. as far as I see these users are running centos, means 2.6.18 kernel.

http://serverfault.com/questions/184607/good-easy-free-vpn-solution-you-can-use-with-openvz

http://www.webhostingtalk.com/archive/index.php/t-956715.html

So from what I can see other people have ppp working on OpenVZ, but I can't get it to work on Proxmox.

Regards,
Patrick.

did you try it with our 2.6.18? as other can run it on 2.6.18 it is very likely that it is also possible here.
 
Tom,

I have just finished building a new Proxmox testing system on version 1.5 and kernel 2.6.18.

I can confirm on kernel 2.6.18 that ppp does work in the VE.

Given this functionality has been lost in the newer kernel versions, do you think it will be included in new versions? (I will need this functionality going forward)

Regards,
Patrick.
 
Tom,

Is there a safe way to downgrade from 2.6.32 to 2.6.18?

It would be much easier to downgrade my main systems than to start again.

I have seen that people are downgrading in the forums, but I can't find the way to do it, but I have also seen other posts to say that it is not possible.

Regards,
Patrick.
 

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