{"id":355,"date":"2010-12-27T23:05:00","date_gmt":"2010-12-27T23:05:00","guid":{"rendered":"http:\/\/zensonic.dk\/?p=355"},"modified":"2017-04-09T10:03:43","modified_gmt":"2017-04-09T10:03:43","slug":"graphing-data-obtained-from-the-zyxel-zynos-ras-interface-in-cacti","status":"publish","type":"post","link":"https:\/\/zensonic.dk\/?p=355","title":{"rendered":"Graphing data obtained from the zyxel zynos ras interface in cacti"},"content":{"rendered":"

After a brief IRC session on ADSL and noise levels with some former colleagues<\/a>, I decided to graph the line quality of my ADSL connection using cacti<\/a>. This blog post will briefly explain how to graph any<\/strong> data that can be obtained from the zyxel zynos ras interface. The data will be graphed using cacti and this blog assumes that a working cacti installation already is running.<\/p>\n

The task at hand can be split into two:<\/p>\n

    \n
  1. Obtaining data from a zyxel device (a P-2602R<\/a> in my case)<\/li>\n
  2. Graphing the data in cacti<\/li>\n<\/ol>\n

    Obtaining data from a zyxel device<\/h3>\n

    I attacked the first problem by doing an snmpwalk of the zyxel device. A normal consumer zyxel ADSL router like the P-2602R will export two MIB trees:<\/p>\n

      \n
    1. The normal iso.3.6.1.2.1 tree<\/li>\n
    2. The private iso.3.6.1.4.1.890 tree<\/li>\n<\/ol>\n

      This can be seen by doing a normal SNMP walk of the device:<\/p>\n

      \n
      edison%  snmpwalk -v1 -c public 192.168.1.1 | head -2
      \niso.3.6.1.2.1.1.1.0 = STRING: "P-2602R-D1A"
      \niso.3.6.1.2.1.1.2.0 = OID: iso.3.6.1.4.1.890<\/div>\n<\/div>\n

      A quick browse of the two MIB trees made it clear that not all values and parameters inside zynos was exported through SNMP.\u00c2\u00a0 I had to find another way of obtaining the values that I needed.<\/p>\n

      Besides utilizing SNMP one, can make a telnet session to the zyxel device, whereby you end up at a RAS prompt. From there you can interface and control a zyxel device in great detail. You will probably need a password for this to work. Living in denmark, having telenor<\/a> as my ISP,\u00c2\u00a0 it is actually fairly easy as I, as\u00c2\u00a0 a customer, has access to all the information needed, ie. ipaddress of the ADSL router, the password and port information. Using this information, I logged into the router<\/p>\n

      \n
      telnet 192.168.1.1 23023
      \nTrying 192.168.1.1…
      \nConnected to 192.168.1.1.
      \nEscape character is ‘^]’.
      \nPassword: **********<\/p>\n

      Copyright (c) 1994 – 2008 ZyXEL Communications Corp.<\/p>\n

      ras&gt;<\/p>\n<\/div>\n<\/div>\n

      From there it was fairly easy to find the information that I was looking for<\/p>\n

      \n
      ras&gt; wan adsl linedata near
      \nnoise margin downstream: 22 db
      \noutput power upstream: 15 db
      \nattenuation downstream: 12 db<\/div>\n<\/div>\n

      Now I just needed be able to do this automatically. I used the unix tool expect<\/a> in the form of the nice and easy to use Expect.pm<\/a> perl module. After 15-20 minutes of coding, I ended up with a little script<\/a> that will fetch whatever values from the zynos ras prompt your heart desires in one go. Example usage of the script (XXXXXXX denotes the secret password)<\/p>\n

      \n
      edison% .\/query_zynos_ras.pl 192.168.1.1 23023 XXXXXXXX "wan adsl  linedata near" "noise margin downstream:" "attenuation downstream:"<\/p>\n

      noise:22 attenuation:12<\/p>\n<\/div>\n<\/div>\n

      Graphing the data in cacti<\/h3>\n

      Now that the data collection had been scripted the data had to be graphed in cacti. This involved defining<\/p>\n