[pptp-server] PPTP masquerade

[Josh Howlett]

Hi all,

Has anyone managed to masquerade PPTP clients and got them to talk to
pptpd?  I'm working on the following set-up:

 PPTP client-\
             |
 PPTP client---Masq--(ip)--PPTP server
             |
 PPTP client-/

It works fine for a single PPTP client, but if a second attempts to
connect to the same server I get this:

Jun 22 10:52:58 cypri pptpd[23386]: CTRL: Client 137.222.12.160 control
connection started
Jun 22 10:52:58 cypri pptpd[23386]: CTRL: Starting call (launching pppd,
opening GRE)
Jun 22 10:52:58 cypri pptpd[23327]: Discarding out-of-order packet 1,
already have 216
Jun 22 10:52:58 cypri pppd[23387]: pppd 2.4.0 started by root, uid 0
Jun 22 10:52:58 cypri pppd[23387]: Using interface ppp1
Jun 22 10:52:58 cypri pppd[23387]: Connect: ppp1 <--> /dev/pts/2
Jun 22 10:52:58 cypri pptpd[23386]: Buffering out-of-order packet; got 1
after 4294967295
Jun 22 10:52:58 cypri pptpd[23327]: Discarding out-of-order packet 2,
already have 216
Jun 22 10:52:58 cypri pptpd[23386]: Packet reorder timeout waiting for 0
Jun 22 10:52:58 cypri pptpd[23386]: Buffering out-of-order packet; got 2
after 0
Jun 22 10:52:58 cypri pptpd[23386]: Missing 12 consecutive packets; got
217 after 2
Jun 22 10:52:58 cypri pptpd[23327]: Discarding out-of-order packet 3,
already have 217
Jun 22 10:52:58 cypri pptpd[23386]: Discarding out-of-order packet 3,
already have 217
Jun 22 10:52:58 cypri pptpd[23327]: Discarding out-of-order packet 4,
already have 217
Jun 22 10:52:58 cypri pptpd[23386]: Discarding out-of-order packet 4,
already have 217
Jun 22 10:53:01 cypri pptpd[23327]: Discarding out-of-order packet 5,
already have 217

I've read (and followed) the VPN masquerade HOWTO, and it says that this
set-up is possible assuming the server allow multiple control channels
to the same IP address.

Does poptop allow this?  Or could I being doing something else wrong?

thanks, josh.

---------------------------------------
Josh Howlett, Network Supervisor,
Networking & Digital Communications,
Information Systems & Computing,
University of Bristol, U.K.
0117 928 7850 | josh.howlett at bris.ac.uk
---------------------------------------