Asus Router as VPN server. Where are the logs?

Question

I'm using my ASUS router at home to provide internet access to a friend living in an internet-unfriendly country.

I've set up the built-in PPTP server with a login and password. I'm using a rather secure username and password but I'm still afraid that a lay person may steal it somehow (partly because I communicate with my friend thru a social network known to give away users' private messages). So I'm afraid that someone can get access to my home network.

I want to be able to see who have been using my VPN over time. Current VPN Server screen shows only present connections which disappear on disconnect.

Current Firmware Version:3.0.0.4.374_880 Model: RT-N12VP

Maybe I can just SSH to the router and grep the filesystem? But I have no idea what PPTP implementation does my router use.

Update: I've Telnet'd into my router and here is contents of my /tmp/pptpd/options.pptpd file:

logfile /var/log/pptpd-pppd.log
lock
name *
proxyarp
lcp-echo-failure 10
lcp-echo-interval 6
deflate 0
auth
-chap
nomppe-stateful
+mschap
+mschap-v2
require-mppe-128
nomppe-56
require-mppe-40
ms-ignore-domain
chap-secrets /tmp/pptpd/chap-secrets
ip-up-script /tmp/pptpd/ip-up
ip-down-script /tmp/pptpd/ip-down
mtu 1450
mru 1450
ms-dns 8.8.8.8
ms-dns 8.8.4.4
minunit 10

Udpate: Here is output of ps

/tmp/pptpd# ps
  PID USER       VSZ STAT COMMAND
    1 admin     1796 S    /sbin/init noinitrd
    2 admin        0 SW<  [kthreadd]
    3 admin        0 SWN  [ksoftirqd/0]
    4 admin        0 SW<  [events/0]
    5 admin        0 SW<  [khelper]
   18 admin        0 SW<  [kblockd/0]
   36 admin        0 SW   [pdflush]
   37 admin        0 SW   [pdflush]
   38 admin        0 SW<  [kswapd0]
   39 admin        0 SW<  [aio/0]
   83 admin        0 SW<  [mtdblockd]
  100 admin        0 SW<  [kmmcd]
  104 admin      596 S    hotplug2 --persistent --no-coldplug
  133 admin     1780 S    console
  134 admin     1252 S    /bin/sh
  177 admin     1788 S    /sbin/wanduck
  180 admin     1036 S    /bin/eapd
  185 admin     1428 S    nas
  186 admin     1900 S    /bin/wps_monitor
  187 admin     1788 S    wpsaide
  190 nobody    1084 S    dnsmasq --log-async
  192 admin     1016 S    /usr/sbin/infosvr br0
  193 admin     1020 S    networkmap
  195 admin     2040 S    watchdog
  197 admin     1220 S    rstats
  198 admin     1788 S    ots
  206 admin     1084 S    lld2d br0
  220 admin     1248 S    udhcpc -i eth0 -p /var/run/udhcpc0.pid -s /tmp/udhcp
  222 admin     1456 S    /usr/sbin/pppd file /tmp/ppp/options.wan0
  306 admin     1788 S    ntp
15833 admin      740 S    miniupnpd -f /etc/upnp/config
18085 admin     1240 S    syslogd -m 0 -S -O /tmp/syslog.log -s 256 -l 6
18087 admin     1240 S    /sbin/klogd
18095 admin     1244 S    telnetd
18096 admin     1440 S    httpd
18104 admin      596 S    pptpd -c /tmp/pptpd/pptpd.conf -o /tmp/pptpd/options
18106 admin      604 D    /usr/sbin/bcrelay -i br0 -o ppp[0-9].* -n
18113 admin      604 D    /usr/sbin/bcrelay -i ppp[0-9].* -o br0 -n
18119 admin     1272 S    -sh
18175 admin     1244 R    ps

Answer 1

This particular model of router has a telnet daemon that can be easily enabled by logging in to the admin page and hitting the link http://routerip/telnetd.cgi?enable=1.

From there, you should be able to telnet in, and get a look at the daemon configuration.

However, embedded systems like routers are notorious for having various logging bits either nonworking, cleared frequently, or even dummied out entirely due to the risk of filling up the file system, meaning that that the log file may be gone or empty, regardless of how the daemon is set up. If that's the case, your historical connection info is lost.

If you just need to host a VPN connection for a single person, OpenVPN Access Server provides a dead simple way to do it on any Linux machine and I personally recommend it. It's a paid product, but it's free for up to two simultaneous connections, and will be a lot more reliable and configurable than the pack-in stuff on your router. You may even get more performance out of it.