[pptp-server] Problems with PPTP Client connecting to PPTPD (long)

[Michael McCallum]

Hi,

I'm currently facing some problems with PPTP Client 1.03 connecting to the
PPTPD daemon. I wish to clarify that I do not have any problems establishing
a connection with PPTPD using W2K VPN client. Everything works fine under
W2K VPN client with maximum encryption. But I have problems trying to
connect using a Linux client (PPTP client) to another Linux server (PPTPD
1.1.2).

I'm currently running these setup on both Linux client and server machines:

    1) Linux kernel 2.4.14
    2) Linux-2.4.4-openssl-0.9.6a-mppe.patch applied to the kernel
    3) PPP-2.4.1
    4) ppp-2.4.1-MSCHAPv2-fix.patch applied to PPP-2.4.1
    5) ppp-2.4.1-openssl-0.9.6-mppe-patch applied to PPP-2.4.1
    6) pptpd-1.1.2.tar.gz (development)
    7) pptp-linux-1.0.3-1

This is my 'pptpd.conf'on my Server machine.

option /etc/options
localip 172.16.2.1-99
remoteip 172.16.2.100-200
pidfile /var/run/pptpd.pid

This is the Server '/etc/options' file.

debug
lock
auth
+chap
+chapms
+chapms-v2
mppe-128
mppe-40
mppe-stateless

This is the '/etc/ppp/options' file in the Client machine.

lock
debug
noauth
mppe-40
mppe-128
mppe-stateless

I started 'pptp' with the following parameters:

pptp <server ip> debug name <username>

and got the following errors (GRE: read error: Protocol not available)

Dec  3 09:45:30 compaq pptpd[11467]: MGR: Launching /usr/sbin/pptpctrl to
handle client
Dec  3 09:45:30 compaq pptpd[11467]: CTRL: local address = 172.16.2.2
Dec  3 09:45:30 compaq pptpd[11467]: CTRL: remote address = 172.16.2.101
Dec  3 09:45:30 compaq pptpd[11467]: CTRL: pppd options file = /etc/options
Dec  3 09:45:30 compaq pptpd[11467]: CTRL: Client 10.0.0.1 control
connection started
Dec  3 09:45:30 compaq pptpd[11467]: CTRL: Received PPTP Control Message
(type: 1)
Dec  3 09:45:30 compaq pptpd[11467]: CTRL: Made a START CTRL CONN RPLY
packet
Dec  3 09:45:30 compaq pptpd[11467]: CTRL: I wrote 156 bytes to the client.
Dec  3 09:45:30 compaq pptpd[11467]: CTRL: Sent packet to client
Dec  3 09:45:31 compaq pptpd[11467]: CTRL: Received PPTP Control Message
(type: 7)
Dec  3 09:45:31 compaq pptpd[11467]: CTRL: 0 min_bps, 152 max_bps, 32 window
size
Dec  3 09:45:31 compaq pptpd[11467]: CTRL: Made a OUT CALL RPLY packet
Dec  3 09:45:31 compaq pptpd[11467]: CTRL: Starting call (launching pppd,
opening GRE)
Dec  3 09:45:31 compaq pptpd[11467]: CTRL: pty_fd = 5
Dec  3 09:45:31 compaq pptpd[11467]: CTRL: tty_fd = 6
Dec  3 09:45:31 compaq pptpd[11467]: CTRL: I wrote 32 bytes to the client.
Dec  3 09:45:31 compaq pptpd[11468]: CTRL (PPPD Launcher): Connection speed
= 115200
Dec  3 09:45:31 compaq pptpd[11468]: CTRL (PPPD Launcher): local address =
172.16.2.2
Dec  3 09:45:31 compaq pptpd[11468]: CTRL (PPPD Launcher): remote address =
172.16.2.101
Dec  3 09:45:31 compaq pppd[11468]: pppd 2.4.1 started by root, uid 0
Dec  3 09:45:31 compaq pppd[11468]: using channel 43
Dec  3 09:45:31 compaq pppd[11468]: Using interface ppp0
Dec  3 09:45:31 compaq pppd[11468]: Connect: ppp0 <--> /dev/pts/2
Dec  3 09:45:31 compaq pppd[11468]: sent [LCP ConfReq id=0x1 <asyncmap 0x0>
<auth chap 81> <magic 0xad640a02> <pcomp> <accomp>]
Dec  3 09:45:31 compaq pptpd[11467]: CTRL: Sent packet to client
Dec  3 09:45:31 compaq pptpd[11467]: GRE: read error: Protocol not available
Dec  3 09:45:31 compaq pptpd[11467]: CTRL: PTY read or GRE write failed
(pty,gre)=(5,6)
Dec  3 09:45:31 compaq pptpd[11467]: CTRL: Client 10.0.0.1 control
connection finished
Dec  3 09:45:31 compaq pppd[11468]: Modem hangup
Dec  3 09:45:31 compaq pppd[11468]: Connection terminated.
Dec  3 09:45:31 compaq pppd[11468]: Exit.

Here is the log from the client side:

Dec  3 10:45:02 router01 pptp[9509]:
log[pptp_dispatch_ctrl_packet:pptp_ctrl.c:578]: Client connectio
n established.
Dec  3 10:45:04 router01 pptp[9509]:
log[pptp_dispatch_ctrl_packet:pptp_ctrl.c:701]: Outgoing call es
tablished (call ID 0, peer's call ID 0).
Dec  3 10:45:04 router01 pppd[9511]: pppd 2.4.1 started by root, uid 0
Dec  3 10:45:04 router01 pppd[9511]: using channel 35
Dec  3 10:45:04 router01 pppd[9511]: Using interface ppp0
Dec  3 10:45:04 router01 pppd[9511]: Connect: ppp0 <--> /dev/pts/6
Dec  3 10:45:04 router01 pppd[9511]: sent [LCP ConfReq id=0x1 <asyncmap 0x0>
<magic 0x51e11853> <pcom
p> <accomp>]
Dec  3 10:45:06 router01 pptp[9510]: log[decaps_gre:pptp_gre.c:215]: short
read (4294967295): Protoco
l not available
Dec  3 10:45:06 router01 pppd[9511]: Hangup (SIGHUP)
Dec  3 10:45:06 router01 pppd[9511]: Modem hangup
Dec  3 10:45:06 router01 pppd[9511]: Connection terminated.
Dec  3 10:45:07 router01 pppd[9511]: Exit.
Dec  3 10:45:07 router01 pptp[9509]: log[callmgr_main:pptp_callmgr.c:240]:
Closing connection
Dec  3 10:45:07 router01 pptp[9509]: log[pptp_conn_close:pptp_ctrl.c:307]:
Closing PPTP connection
Dec  3 10:45:07 router01 pptp[9509]: log[pptp_write_some:pptp_ctrl.c:376]:
write error: Broken pipe
Dec  3 10:45:07 router01 pptp[9509]: log[call_callback:pptp_callmgr.c:88]:
Closing connection

All the machines are within the same LAN and have the same subnet/netmask.
So I do not think there are any firewalls which could interfere with the
GRE. My hunch is that the server 'options' and client 'options' files do not
agree with each other? I've would really appreciate if someone could shine a
light at what is wrong with my current config.

Thanks!