WIKI
http://gentoo-wiki.com/HOWTO_Set_up_a_vpn_client_with_mppe_encryption

jmg ~ # pon NMG debug dump logfd 2 nodetach
pppd options in effect:
debug           # (from command line)
nodetach                # (from command line)
logfd 2         # (from command line)
dump            # (from command line)
noauth          # (from /etc/ppp/options.NMG)
name johng              # (from /etc/ppp/peers/NMG)
remotename NMG          # (from /etc/ppp/peers/NMG)
                # (from /etc/ppp/options.NMG)
pty pptp vpn.newmediagateway.com --nolaunchpppd         # (from /etc/ppp/peers/N
MG)
mru 1000                # (from /etc/ppp/options.NMG)
mtu 1000                # (from /etc/ppp/options.NMG)
lcp-echo-failure 10             # (from /etc/ppp/options.NMG)
lcp-echo-interval 10            # (from /etc/ppp/options.NMG)
ipparam NMG             # (from /etc/ppp/peers/NMG)
nobsdcomp               # (from /etc/ppp/options.NMG)
nodeflate               # (from /etc/ppp/options.NMG)
require-mppe            # (from /etc/ppp/options.NMG)
using channel 1
Using interface ppp0
Connect: ppp0 <--> /dev/pts/3
sent [LCP ConfReq id=0x1 <mru 1000> <asyncmap 0x0> <magic 0x1d2bcd1a> <pcomp> <a
ccomp>]
rcvd [LCP ConfReq id=0x14 <accomp> <pcomp> <mru 1500> <magic 0x71605c00> <auth c
hap MS-v2> <mrru 1600> <ssnhf> <endpoint [MAC:00:a0:c9:69:50:f6]>]
sent [LCP ConfRej id=0x14 <mrru 1600> <ssnhf>]
rcvd [LCP ConfAck id=0x1 <mru 1000> <asyncmap 0x0> <magic 0x1d2bcd1a> <pcomp> <a
ccomp>]
rcvd [LCP ConfReq id=0x15 <accomp> <pcomp> <mru 1500> <magic 0x71605c00> <auth c
hap MS-v2>]
sent [LCP ConfAck id=0x15 <accomp> <pcomp> <mru 1500> <magic 0x71605c00> <auth c
hap MS-v2>]
sent [LCP EchoReq id=0x0 magic=0x1d2bcd1a]
rcvd [CHAP Challenge id=0x1 <bb1e6888bec52c5dcd69d9506bb579cf>, name = ""]
sent [CHAP Response id=0x1 <ad3b21a13213d14da83df9f88f45ee1a0042424242424242abee
5ab6de4ef1eb54f30bbe67e970e055590593ab6c1e0f42>, name = "johng"]
rcvd [LCP EchoRep id=0x0 magic=0x71605c00]
rcvd [CHAP Success id=0x1 "S=3AB57AA05E3112BC8846F87C0B5219470905BE1D"]
CHAP authentication succeeded
sent [CCP ConfReq id=0x1 <mppe +H -M +S +L -D -C>]
rcvd [IPCP ConfReq id=0x9 <addr 192.168.1.253> <compress VJ 0f 00>]
sent [IPCP TermAck id=0x9]
rcvd [CCP ConfReq id=0x9 <mppe +H +M +S +L -D -C>]
sent [CCP ConfNak id=0x9 <mppe +H -M +S -L -D -C>]
rcvd [CCP ConfNak id=0x1 <mppe +H -M +S -L -D -C>]
sent [CCP ConfReq id=0x2 <mppe +H -M +S -L -D -C>]
rcvd [CCP ConfReq id=0xa <mppe +H -M +S -L -D -C>]
sent [CCP ConfAck id=0xa <mppe +H -M +S -L -D -C>]
rcvd [CCP ConfAck id=0x2 <mppe +H -M +S -L -D -C>]
MPPE 128-bit stateless compression enabled
sent [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 0.0.0.0>]
rcvd [IPCP ConfNak id=0x1 <addr 192.168.1.194>]
sent [IPCP ConfReq id=0x2 <compress VJ 0f 01> <addr 192.168.1.194>]
rcvd [IPCP ConfAck id=0x2 <compress VJ 0f 01> <addr 192.168.1.194>]
rcvd [IPCP ConfReq id=0xa <addr 192.168.1.253> <compress VJ 0f 00>]
sent [IPCP ConfAck id=0xa <addr 192.168.1.253> <compress VJ 0f 00>]
local  IP address 192.168.1.194
remote IP address 192.168.1.253
Script /etc/ppp/ip-up started (pid 5777)
Script /etc/ppp/ip-up finished (pid 5777), status = 0x1

=============
====================================================
=============

ppp0      Link encap:Point-to-Point Protocol  
          inet addr:192.168.1.194  P-t-P:192.168.1.253  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:996  Metric:1
          RX packets:8 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3 
          RX bytes:98 (98.0 b)  TX bytes:92 (92.0 b)

=============
====================================================
=============

jmg ~ # /etc/init.d/net.ppp0 start
 * Service net.ppp0 starting
 * WARNING:  net.ppp0 has started but is inactive

=============
====================================================
=============

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.1.253   *               255.255.255.255 UH    0      0        0 ppp0
192.168.123.0   *               255.255.255.0   U     0      0        0 eth0
loopback        *               255.0.0.0       U     0      0        0 lo
default         192.168.123.1   0.0.0.0         UG    0      0        0 eth0