[pptp-server] Dial-up problems

Phil Verghese philv at ridgerun.com
Mon Jul 10 19:52:38 CDT 2000 

I've been searching through the archives but haven't found any help for the
problem I'm having.  When I connect to the PPTP server via an ethernet
Internet connection, I have no problems and the connection will stay up.
When I connect via dial-up I can't keep a connection for more than about 10
minutes (usually it's only about 2 minutes).  After x minutes, I get no
response over PPTP, and I get no errors logged on the client or server side.
Before the PPTP link gets unresponsive, everything works fine: ping, telnet,
browsing the Network Neighborhood, etc.

Any help or even hints would be greatly appreciated.  I saw something in the
archives about trying smaller MTU sizes, and I've been experimenting with
that to no avail.  Thanks in advance.

Phil

Here's my configuration:

Server
------
Linux 2.2.16
ppp-2.3.10, with openssl-norc4-mppe and mppe_stateless patches applied
pptpd-1.0.0-1
/proc/sys/net/ipv4/ip_forward is 1

Firewall
--------
Linux 2.2.16
ipmasqadm & ipfwd installed to masquerade and route VPN traffic to server
No rejected packets reported in the logs, so I'm fairly confident there's no
problems here

Clients
------
Windows 98SE
Already did the uninstall/reinstall VPN workaround
Note: I've tried this with multiple clients all configured the same, and
they all have the same behavior.

/etc/ppp/options
----------------
lock
debug
auth
# Refuse normal CHAP authentication (it's insecure)
-chap
# Refuse MS CHAP-v1 authentication (it's insecure)
-chapms
proxyarp
# Require MS CHAP-v2 authentication (it's secure if strong passwords are
used)
+chapms-v2
# Support 40-bit encryption
mppe-40
# Support 128-bit encryption
mppe-128
mppe-stateless
# Added these to see if they will help with keeping the dialup PPTP
connection up
mru 552
mtu 1104

/etc/pptpd.conf
---------------
debug
localip 192.168.1.100-149
remoteip 192.168.1.150-199

Before I include the logs, let me tell you what I did.  On the Windows
client, I established a dial-up connection through my ISP, then started the
VPN dial-up adapter.  The link came up and from a DOS box, I pinged the
server (192.168.1.1) 1000 times by running:
ping -n 1000 192.168.1.1

The client was able to ping the server for about 6 minutes with no problems.
During this time, the server could also ping the client (192.168.1.150).
Then all of a sudden I started to get "Request timed out" messages and the
server could no longer ping the client either.

At that time, I disconnected the VPN dial-up adapter on the client side and
the client and server shutdown gracefully.

snips from /var/log/messages from a session where the problem happened
----------------------------------------------------------------------
Jul 10 17:48:08 ridgerun-lx pptpd[7824]: CTRL: Client 206.206.37.117 control
connection started
Jul 10 17:48:09 ridgerun-lx pptpd[7824]: CTRL: Starting call (launching
pppd, opening GRE)
Jul 10 17:48:09 ridgerun-lx pppd[7825]: pppd 2.3.10 started by philv, uid 0
Jul 10 17:48:09 ridgerun-lx pppd[7825]: Using interface ppp0
Jul 10 17:48:09 ridgerun-lx pppd[7825]: Connect: ppp0 <--> /dev/pts/1
Jul 10 17:48:09 ridgerun-lx pppd[7825]: MSCHAP-v2 peer authentication
succeeded for philv
Jul 10 17:48:10 ridgerun-lx pppd[7825]: found interface eth0 for proxy arp
Jul 10 17:48:10 ridgerun-lx pppd[7825]: local  IP address 192.168.1.100
Jul 10 17:48:10 ridgerun-lx pppd[7825]: remote IP address 192.168.1.150
Jul 10 17:48:10 ridgerun-lx pppd[7825]: MPPE 40 bit, stateless compression
enabled
Jul 10 17:54:52 ridgerun-lx pppd[7825]: LCP terminated by peer
Jul 10 17:54:52 ridgerun-lx pptpd[7824]: CTRL: Error with select(), quitting
Jul 10 17:54:52 ridgerun-lx pptpd[7824]: CTRL: Client 206.206.37.117 control
connection finished
Jul 10 17:54:52 ridgerun-lx pppd[7825]: Modem hangup
Jul 10 17:54:52 ridgerun-lx pppd[7825]: Connection terminated.
Jul 10 17:54:52 ridgerun-lx pppd[7825]: Connect time 6.8 minutes.
Jul 10 17:54:52 ridgerun-lx pppd[7825]: Sent 33651 bytes, received 34992
bytes.
Jul 10 17:54:52 ridgerun-lx pppd[7825]: Exit.

ppplog.txt from the Windows client machine
------------------------------------------
07-10-2000 17:48:08.28 - Microsoft Dial Up Adapter log opened.
07-10-2000 17:48:08.28 - Server type is  PPP (Point to Point Protocol).
07-10-2000 17:48:08.28 - FSA : Adding Control Protocol 80fd (CCP) to control
protocol chain.
07-10-2000 17:48:08.28 - FSA : Protocol not bound - skipping control
protocol 803f (NBFCP).
07-10-2000 17:48:08.28 - FSA : Adding Control Protocol 8021 (IPCP) to
control protocol chain.
07-10-2000 17:48:08.28 - FSA : Protocol not bound - skipping control
protocol 802b (IPXCP).
07-10-2000 17:48:08.28 - FSA : Adding Control Protocol c029 (CallbackCP) to
control protocol chain.
07-10-2000 17:48:08.28 - FSA : Encrypted Password required.
07-10-2000 17:48:08.28 - FSA : Encrypted Password required.
07-10-2000 17:48:08.28 - FSA : Adding Control Protocol c223 (CHAP) to
control protocol chain.
07-10-2000 17:48:08.28 - FSA : Adding Control Protocol c021 (LCP) to control
protocol chain.
07-10-2000 17:48:08.28 - LCP : Layer started.
07-10-2000 17:48:08.28 - PPP : Transmitting Control Packet of length: 16
07-10-2000 17:48:08.28 - Data 0000: c0 21 01 01 00 0e 05 06 | .!......
07-10-2000 17:48:08.28 - Data 0008: 00 04 bd 18 07 02 08 02 | .......
07-10-2000 17:48:08.45 - PPP : Received Control Packet of length: 31
07-10-2000 17:48:08.45 - Data 0000: c0 21 01 01 00 1d 01 04 | .!...
..
07-10-2000 17:48:08.45 - Data 0008: 02 28 02 06 00 00 00 00 | .(......
07-10-2000 17:48:08.45 - Data 0010: 03 05 c2 23 81 05 06 74 | ...#...t
07-10-2000 17:48:08.45 - Data 0018: d8 14 22 07 02 08 02 00 | ..".....
07-10-2000 17:48:08.45 - LCP : Received and accepted MRU of 552.
07-10-2000 17:48:08.45 - LCP : Received and accepted ACCM of 0.
07-10-2000 17:48:08.45 - LCP : Received and accepted authentication protocol
c223 (CHAP).
07-10-2000 17:48:08.45 - LCP : Received and accepted magic number 74d81422.
07-10-2000 17:48:08.45 - LCP : Received and accepted protocol field
compression option.
07-10-2000 17:48:08.45 - LCP : Received and accepted address+control field
compression option.
07-10-2000 17:48:08.45 - PPP : Transmitting Control Packet of length: 31
07-10-2000 17:48:08.45 - Data 0000: c0 21 02 01 00 1d 01 04 | .!...
..
07-10-2000 17:48:08.45 - Data 0008: 02 28 02 06 00 00 00 00 | .(......
07-10-2000 17:48:08.45 - Data 0010: 03 05 c2 23 81 05 06 74 | ...#...t
07-10-2000 17:48:08.45 - Data 0018: d8 14 22 07 02 08 02 00 | ..".....
07-10-2000 17:48:08.45 - PPP : Received Control Packet of length: 16
07-10-2000 17:48:08.45 - Data 0000: c0 21 02 01 00 0e 05 06 | .!......
07-10-2000 17:48:08.45 - Data 0008: 00 04 bd 18 07 02 08 02 | .......
07-10-2000 17:48:08.45 - LCP : Layer up.
07-10-2000 17:48:08.45 - CHAP : Layer started.
07-10-2000 17:48:08.64 - PPP : Received Control Packet of length: 47
07-10-2000 17:48:08.64 - Data 0000: c2 23 01 01 00 2d 10 c8 | .#...-..
07-10-2000 17:48:08.64 - Data 0008: e5 22 16 0e 1c 47 37 44 | .".
G7D
07-10-2000 17:48:08.64 - Data 0010: 6c 66 21 56 ab 9b 35 72 | lf!V..5r
07-10-2000 17:48:08.64 - Data 0018: 69 64 67 65 72 75 6e 2d | idgerun-
07-10-2000 17:48:08.64 - Data 0020: 6c 78 2e 72 69 64 67 65 | lx.ridge
07-10-2000 17:48:08.64 - Data 0028: 72 75 6e 2e 63 78 6d 00 | run.cxm.
07-10-2000 17:48:08.64 - PPP : Transmitting Control Packet of length: 61
07-10-2000 17:48:08.64 - Data 0000: c2 23 02 01 00 3b 31 c3 | .#...;1.
07-10-2000 17:48:08.64 - Data 0008: 52 ed 5c 25 6b aa bb 80 | R.\%k...
07-10-2000 17:48:08.64 - Data 0010: 1c 98 39 99 f6 bb e9 00 | 
.9.....
07-10-2000 17:48:08.64 - Data 0018: 00 00 00 00 00 00 00 a2 | ........
07-10-2000 17:48:08.64 - Data 0020: b8 c0 97 d0 2b b5 9c 24 | ....+..$
07-10-2000 17:48:08.64 - Data 0028: 4b 52 61 48 61 09 ee fc | KRaHa...
07-10-2000 17:48:08.64 - Data 0030: 71 16 36 87 dd a1 11 04 | q6.....
07-10-2000 17:48:08.64 - Data 0038: 70 68 69 6c 76 00 00 00 | philv...
07-10-2000 17:48:08.86 - PPP : Received Control Packet of length: 48
07-10-2000 17:48:08.86 - Data 0000: c2 23 03 01 00 2e 53 3d | .#....S=
07-10-2000 17:48:08.86 - Data 0008: 41 33 44 44 46 45 37 33 | A3DDFE73
07-10-2000 17:48:08.86 - Data 0010: 46 43 34 31 39 34 39 41 | FC41949A
07-10-2000 17:48:08.86 - Data 0018: 35 38 42 36 31 32 31 31 | 58B61211
07-10-2000 17:48:08.86 - Data 0020: 34 33 33 34 44 42 43 32 | 4334DBC2
07-10-2000 17:48:08.86 - Data 0028: 46 46 45 35 42 34 36 38 | FFE5B468
07-10-2000 17:48:08.86 - CHAP : Login was successful.
07-10-2000 17:48:08.86 - CHAP : Layer up.
07-10-2000 17:48:08.86 - IPCP : Layer started.
07-10-2000 17:48:08.86 - IPCP : IP address is 0.
07-10-2000 17:48:08.86 - CCP : Layer started.
07-10-2000 17:48:08.86 - PPP : Transmitting Control Packet of length: 36
07-10-2000 17:48:08.86 - Data 0000: 80 21 01 01 00 22 03 06 | .!..."..
07-10-2000 17:48:08.86 - Data 0008: 00 00 00 00 81 06 00 00 | ........
07-10-2000 17:48:08.86 - Data 0010: 00 00 82 06 00 00 00 00 | ........
07-10-2000 17:48:08.86 - Data 0018: 83 06 00 00 00 00 84 06 | ........
07-10-2000 17:48:08.86 - Data 0020: 00 00 00 00 00 00 00 00 | ........
07-10-2000 17:48:08.86 - PPP : Transmitting Control Packet of length: 17
07-10-2000 17:48:08.86 - Data 0000: 80 fd 01 01 00 0f 12 06 | ........
07-10-2000 17:48:08.86 - Data 0008: 01 00 00 31 11 05 00 01 | ...1....
07-10-2000 17:48:08.86 - Data 0010: 04 00 00 00 00 00 00 00 | ........
07-10-2000 17:48:08.86 - PPP : Received Control Packet of length: 18
07-10-2000 17:48:08.86 - Data 0000: 80 21 01 01 00 10 03 06 | .!......
07-10-2000 17:48:08.86 - Data 0008: c0 a8 01 64 02 06 00 2d | ...d...-
07-10-2000 17:48:08.86 - Data 0010: 0f 01 00 00 00 00 00 00 | ........
07-10-2000 17:48:08.86 - IPCP : Received and accepted IP address of
c0a80164.
07-10-2000 17:48:08.86 - PPP : Transmitting Control Packet of length: 12
07-10-2000 17:48:08.86 - Data 0000: 80 21 04 01 00 0a 02 06 | .!......
07-10-2000 17:48:08.86 - Data 0008: 00 2d 0f 01 00 00 00 00 | .-......
07-10-2000 17:48:08.87 - PPP : Received Control Packet of length: 23
07-10-2000 17:48:08.87 - Data 0000: 80 fd 01 01 00 15 1a 04 | ......
07-10-2000 17:48:08.87 - Data 0008: 78 00 18 04 78 00 12 06 | x..x...
07-10-2000 17:48:08.87 - Data 0010: 01 00 00 60 15 03 2f 00 | ...`./.
07-10-2000 17:48:08.87 - PPP : Transmitting Control Packet of length: 17
07-10-2000 17:48:08.87 - Data 0000: 80 fd 04 01 00 0f 1a 04 | .......
07-10-2000 17:48:08.87 - Data 0008: 78 00 18 04 78 00 15 03 | x..x..
07-10-2000 17:48:08.87 - Data 0010: 2f 00 00 00 00 00 00 00 | /.......
07-10-2000 17:48:09.03 - PPP : Received Control Packet of length: 30
07-10-2000 17:48:09.03 - Data 0000: 80 21 04 01 00 1c 81 06 | .!...
..
07-10-2000 17:48:09.03 - Data 0008: 00 00 00 00 82 06 00 00 | ........
07-10-2000 17:48:09.03 - Data 0010: 00 00 83 06 00 00 00 00 | ........
07-10-2000 17:48:09.03 - Data 0018: 84 06 00 00 00 00 00 00 | ........
07-10-2000 17:48:09.03 - PPP : Transmitting Control Packet of length: 12
07-10-2000 17:48:09.03 - Data 0000: 80 21 01 02 00 0a 03 06 | .!......
07-10-2000 17:48:09.03 - Data 0008: 00 00 00 00 00 00 00 00 | ........
07-10-2000 17:48:09.04 - PPP : Received Control Packet of length: 11
07-10-2000 17:48:09.04 - Data 0000: 80 fd 04 01 00 09 11 05 | ........
07-10-2000 17:48:09.04 - Data 0008: 00 01 04 00 00 00 00 00 | ........
07-10-2000 17:48:09.04 - PPP : Transmitting Control Packet of length: 12
07-10-2000 17:48:09.04 - Data 0000: 80 fd 01 02 00 0a 12 06 | ........
07-10-2000 17:48:09.04 - Data 0008: 01 00 00 31 00 00 00 00 | ...1....
07-10-2000 17:48:09.07 - PPP : Received Control Packet of length: 12
07-10-2000 17:48:09.07 - Data 0000: 80 21 01 02 00 0a 03 06 | .!......
07-10-2000 17:48:09.07 - Data 0008: c0 a8 01 64 00 00 00 00 | ...d....
07-10-2000 17:48:09.07 - IPCP : Received and accepted IP address of
c0a80164.
07-10-2000 17:48:09.07 - PPP : Transmitting Control Packet of length: 12
07-10-2000 17:48:09.07 - Data 0000: 80 21 02 02 00 0a 03 06 | .!......
07-10-2000 17:48:09.07 - Data 0008: c0 a8 01 64 00 00 00 00 | ...d....
07-10-2000 17:48:09.07 - PPP : Received Control Packet of length: 12
07-10-2000 17:48:09.07 - Data 0000: 80 fd 01 02 00 0a 12 06 | ........
07-10-2000 17:48:09.07 - Data 0008: 01 00 00 60 00 00 00 00 | ...`....
07-10-2000 17:48:09.07 - CCP : NAK unrecognized compression value 40.
07-10-2000 17:48:09.07 - PPP : Transmitting Control Packet of length: 12
07-10-2000 17:48:09.07 - Data 0000: 80 fd 03 02 00 0a 12 06 | ........
07-10-2000 17:48:09.07 - Data 0008: 01 00 00 20 00 00 00 00 | ... ....
07-10-2000 17:48:09.21 - PPP : Received Control Packet of length: 12
07-10-2000 17:48:09.21 - Data 0000: 80 21 03 02 00 0a 03 06 | .!......
07-10-2000 17:48:09.21 - Data 0008: c0 a8 01 96 00 00 00 00 | ........
07-10-2000 17:48:09.21 - IPCP : Changing IP address from 0 to c0a80196.
07-10-2000 17:48:09.21 - PPP : Transmitting Control Packet of length: 12
07-10-2000 17:48:09.21 - Data 0000: 80 21 01 03 00 0a 03 06 | .!......
07-10-2000 17:48:09.21 - Data 0008: c0 a8 01 96 00 00 00 00 | ........
07-10-2000 17:48:09.22 - PPP : Received Control Packet of length: 12
07-10-2000 17:48:09.22 - Data 0000: 80 fd 03 02 00 0a 12 06 | ........
07-10-2000 17:48:09.22 - Data 0008: 01 00 00 60 00 00 00 00 | ...`....
07-10-2000 17:48:09.22 - CCP : NAK unrecognized compression value 40.
07-10-2000 17:48:09.22 - PPP : Transmitting Control Packet of length: 12
07-10-2000 17:48:09.22 - Data 0000: 80 fd 01 03 00 0a 12 06 | ........
07-10-2000 17:48:09.22 - Data 0008: 01 00 00 20 00 00 00 00 | ... ....
07-10-2000 17:48:09.30 - PPP : Received Control Packet of length: 12
07-10-2000 17:48:09.30 - Data 0000: 80 fd 01 03 00 0a 12 06 | ........
07-10-2000 17:48:09.30 - Data 0008: 01 00 00 20 00 00 00 00 | ... ....
07-10-2000 17:48:09.30 - CCP : Received and accepted compression value
1000020.
07-10-2000 17:48:09.30 - PPP : Transmitting Control Packet of length: 12
07-10-2000 17:48:09.30 - Data 0000: 80 fd 02 03 00 0a 12 06 | ........
07-10-2000 17:48:09.30 - Data 0008: 01 00 00 20 00 00 00 00 | ... ....
07-10-2000 17:48:09.37 - PPP : Received Control Packet of length: 12
07-10-2000 17:48:09.37 - Data 0000: 80 21 02 03 00 0a 03 06 | .!......
07-10-2000 17:48:09.37 - Data 0008: c0 a8 01 96 00 00 00 00 | ........
07-10-2000 17:48:09.37 - IPCP : Layer up.
07-10-2000 17:48:09.39 - PPP : Received Control Packet of length: 12
07-10-2000 17:48:09.39 - Data 0000: 80 fd 02 03 00 0a 12 06 | ........
07-10-2000 17:48:09.39 - Data 0008: 01 00 00 20 00 00 00 00 | ... ....
07-10-2000 17:48:09.39 - CCP : Layer up.
07-10-2000 17:48:09.39 - FSA : Last control protocol is up.
07-10-2000 17:54:51.53 - Remote access driver is shutting down.
07-10-2000 17:54:51.53 - CRC Errors             0
07-10-2000 17:54:51.53 - Timeout Errors         0
07-10-2000 17:54:51.53 - Alignment Errors       0
07-10-2000 17:54:51.53 - Overrun Errors         0
07-10-2000 17:54:51.53 - Framing Errors         0
07-10-2000 17:54:51.53 - Buffer Overrun Errors  0
07-10-2000 17:54:51.53 - Incomplete Packets     0
07-10-2000 17:54:51.53 - Bytes Received         28438
07-10-2000 17:54:51.53 - Bytes Transmittted     29327
07-10-2000 17:54:51.53 - Frames Received        409
07-10-2000 17:54:51.53 - Frames Transmitted     441
07-10-2000 17:54:51.53 - LCP : Layer down.
07-10-2000 17:54:51.53 - CHAP : Layer down.
07-10-2000 17:54:51.53 - IPCP : Layer down.
07-10-2000 17:54:51.53 - CCP : Layer down.
07-10-2000 17:54:51.53 - PPP : Transmitting Control Packet of length: 6
07-10-2000 17:54:51.53 - Data 0000: c0 21 05 02 00 04 00 00 | .!......
07-10-2000 17:54:51.70 - PPP : Received Control Packet of length: 6
07-10-2000 17:54:51.70 - Data 0000: c0 21 06 02 00 04 00 00 | .!......
07-10-2000 17:54:51.70 - LCP : Received terminate acknowledgement.
07-10-2000 17:54:51.70 - LCP : Layer finished.
07-10-2000 17:54:51.70 - Microsoft Dial Up Adapter log closed.

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