Hello. Just started to play with pptp under Linux. Everything looks ok except mppe.
mppe encrypted ping -c1:
ping source side:
# tcpdump -nlippp0 -s0 -vvv -xX
tcpdump: listening on ppp0, link-type LINUX_SLL (Linux cooked), capture size
65535 bytes
23:15:07.968863 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], length: 84)
1.1.6.2 > 1.1.6.1: icmp 64: echo request seq 1
0x0000 0004 0200 0000 0000 0000 0000 0000 0800 ................
0x0010 4500 0054 0000 4000 4001 2ca5 0101 0602 E..T..@.@.,.....
0x0020 0101 0601 0800 1f1f a613 0001 4bc0 ab40 ............K..@
0x0030 42c8 0e00 0809 0a0b 0c0d 0e0f 1011 1213 B...............
0x0040 1415 1617 1819 1a1b 1c1d 1e1f 2021 2223 .............!"#
0x0050 2425 2627 2829 2a2b 2c2d 2e2f 3031 3233 $%&'()*+,-./0123
0x0060 3435 3637 4567
ping target side:
# tcpdump -nlippp0 -s0 -vvv -xX
tcpdump: listening on ppp0, link-type LINUX_SLL (Linux cooked), capture size
65535 bytes
23:15:01.521393 IP truncated-ip - 3 bytes missing! (tos 0x0, ttl 64, id 0,
offset 0, flags [DF], length: 84) 1.1.6.2 > 1.1.6.1: icmp 64: echo
0x0000 0000 0200 0000 0000 0000 0000 0000 0800 ................
0x0010 4500 0054 0000 4000 4001 2ca5 0101 0602 E..T..@.@.,.....
0x0020 0101 0601 0800 1f1f a613 0001 4bc0 ab40 ............K..@
0x0030 42c8 0e00 0809 0a0b 0c0d 0e0f 1011 1213 B...............
0x0040 1415 1617 1819 1a1b 1c1d 1e1f 2021 2223 .............!"#
0x0050 2425 2627 2829 2a2b 2c2d 2e2f 3031 3233 $%&'()*+,-./0123
0x0060 34 4
If I run exactly the same config but with 'require-mppe' removed
from configs on both client and server side, this does not happen.
versions (identical for server and client)
========
poptop-1.1.4
ppp-2.4.2_cvs_20021120
pptp-linux-1.2.0
linux-2.6.6 patched with kernelmod-0.8/2.6/* files.
I rediffed patch against 2.6.5.
Patch is attached.
Was applied to 2.6.6 (with offsets).
server
======
pppd options file:
mru 1467
mtu 1467
logfd 2
require-mppe
require-mschap-v2
debug
show-password
name PPTP
remotename test
pptpd conf file:
localip 1.1.6.1
remoteip 1.1.6.2-255
pptpd \
--conf "$PWD/pptpd.conf" \
--option "$PWD/options.pptpd.mppe" \
--debug \
--fg \
--pidfile /dev/null
client
======
pppd options file: (empty)
pppd \
noipdefault \
name test \
remotename PPTP \
nodefaultroute \
noproxyarp \
nodetach \
logfd 2 \
noauth \
nobsdcomp \
nodeflate \
require-mppe \
nomppe-stateful \
debug \
show-password \
mru 1467 \
mtu 1467 \
lcp-echo-failure 3 \
lcp-echo-interval 27 \
maxfail 1 \
pty "pptp 1.1.1.1 --nolaunchpppd" \
--
vda
linux-2.6.5.mppe.patch.gz
Description: GNU Zip compressed data
