[l2tp] Connect to Company Network Skill

touch /var/run/xl2tpd/l2tp-control

0. Install

sudo aptitude install xl2tpd

Correct one

1. Edit /etc/xl2tpd/xl2tpd.conf

;
; Sample l2tpd configuration file
;
; This example file should give you some idea of how the options for l2tpd
; should work.  The best place to look for a list of all options is in
; the source code itself, until I have the time to write better documetation :)
; Specifically, the file "file.c" contains a list of commands at the end.
;
; You most definitely don't have to spell out everything as it is done here
;
[global]                ; Global parameters:
debug tunnel = yes;

[lac testvpn]
lns = "The IP of remote of WAN IP"
name = "The authorize name of remote WAN IP"
require chap = yes
refuse pap = yes
require authentication = no
ppp debug = no
pppoptfile = /etc/ppp/options.xl2tpd.client
length bit = yes

My /etc/ppp/options.xl2tpd.client of content

ipcp-accept-local
ipcp-accept-remote
ms-dns 168.95.1.1
ms-dns 8.8.8.8
ms-wins 111.2.1.2
ms-wins 111.2.1.4
noccp
auth
crtscts
idle 1800
nodefaultroute
debug
lock
proxyarp
connect-delay 5000
logfile /var/log/xl2tpd.log

2. Edit /etc/ppp/chap-secrets 

# Secrets for authentication using CHAP
# client        server  secret                  IP addresses
"Account of remote WANIP"  *    "Password of remote WANIP"        *
abc  *    abc1234       *

3. Start daemon

xl2tpd -c /etc/xl2tpd/xl2tpd.conf -D

Create VPN tunnel
echo 'c testvpn' >/var/run/xl2tpd/l2tp-control

Wait for 2 second.
And type ifconfig will see ppp0

Destroy VPN tunnel
echo "d testvpn" >/var/run/xl2tpd/l2tp-control

4. Add "Remote WAN IP address" as LAN IP address
Go through gateway is depend on you internet

For example :
My internet setting is

wlan0     Link encap:Ethernet  HWaddr 48:5D:60:35:2A:B0
          inet addr:192.168.2.101  Bcast:192.168.2.255  Mask:255.255.255.0
          inet6 addr: fe80::4a5d:60ff:fe35:2ab0/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:9854 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1055 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1321131 (1.2 MiB)  TX bytes:183435 (179.1 KiB)

So the Gateway is 192.168.2.1

route add -host "Remote WAN IP address" gw 192.168.2.1
ex: route add -host 1.2.3.4 gw 192.168.2.1

route add default ppp0

5. ping any machine of your company
ping x.x.x.x

If you get response.
Congratulation you are successfully.

PS1:

After step 5  using traceroute.

And traceroute 8.8.8.8.

Will see route packet to defferent way out

root@YA-laptop:~# traceroute 8.8.8.8
traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets
 1  10.10.101.1 (10.10.101.1)  63.703 ms  63.633 ms  67.763 ms
 2  222-222-222-254.HINET-IP.hinet.net (222.222.222.254)  103.519 ms  103.478 ms  103.439 ms
 3  h122.s208.ts.hinet.net (168.95.208.122)  103.399 ms  111.391 ms  111.351 ms
 4  SCZS-3101.hinet.net (220.128.7.82)  114.293 ms SCZS-3102.hinet.net (220.128.7.102)  111.269 ms  114.212 ms
 5  TPDT-3012.hinet.net (220.128.2.34)  118.192 ms TPDT-3011.hinet.net (220.128.1.90)  118.155 ms  122.301 ms
 6  TYFO-3011.hinet.net (220.128.3.105)  127.286 ms  175.703 ms TYFO-3012.hinet.net (220.128.4.105)  175.635 ms
 7  TYFO-3302.hinet.net (220.128.9.197)  139.454 ms 220-128-8-189.HINET-IP.hinet.net (220.128.8.189)  139.386 ms  139.349 ms

ifcnofig is :

ppp0      Link encap:Point-to-Point Protocol
          inet addr:10.10.101.20  P-t-P:10.10.101.1  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1410  Metric:1
          RX packets:3 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3
          RX bytes:42 (42.0 B)  TX bytes:48 (48.0 B)

route is :

root@YA-laptop:~# route -n
Kernel IP routing table
Destination            Gateway            Genmask             Flags        Metric    Ref    Use   Iface
10.10.101.1              0.0.0.0        255.255.255.255        UH            0        0      0    ppp0
222.222.222.222        192.168.1.1      255.255.255.255        UGH           0        0      0    wlan0
192.168.1.0              0.0.0.0          255.255.255.0        U             2        0      0    wlan0
0.0.0.0                  0.0.0.0          0.0.0.0              U             0        0      0    ppp0
0.0.0.0                192.168.1.1         0.0.0.0             UG            0        0      0    wlan0

PS2 .

If you have use linux OS

You can type " route -n " to find out  what is the gateway you got.

HAPPY@HAPPY-laptop:~$ route -n
Kernel IP routing table
Destination        Gateway      Genmask        Flags  Metric   Ref   Use Iface
172.16.146.0      0.0.0.0     255.255.255.0      U     0        0     0 vmnet8
192.168.178.0   0.0.0.0       255.255.255.0      U     0        0     0 vmnet1
192.168.1.0        0.0.0.0    255.255.255.0      U     1        0     0 eth0
192.168.1.0      0.0.0.0      255.255.255.0      U     2        0     0 wlan0
169.254.0.0      0.0.0.0      255.255.0.0        U     1000     0     0 eth0
0.0.0.0         192.168.1.1     0.0.0.0          UG    0        0     0 eth0

The blue word is gateway.


vmnet8 & vmnet1 is IP address of VMware.

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Reference:

• 用xl2tpd建立L2TP协议的VPN连接

Comment :

I find so many document at 2:03 PM. I write it down at 20120106 at 2:51 AM. When 2:51 AM. My father saw my light was still light.He so angry come to upstair and yell me. So I must go to sleep.