SNMP exercises, part 1
                                  SANOG 10

1. Getting packages

    # apt-get install snmp
    # apt-get install snmpd
    # apt-get install mbrowse

2. GET and WALK

    To control that your SNMP installation works:

    - The backbone router:

    # snmpstatus -c san0g -v1 169.223.1.1

    - The classroom switch:

    # snmpstatus -c san0g -v1 169.223.5.253

    - Try to snmpwalk different parts of these equipments' MIBs:

    # snmpwalk -c san0g -v1 169.223.1.1 1.3.6.1.4.1.9.9.13.1.3 | more
    # ...

    Do you notice anything important about the OID on the output ?

3. Configuration of snmpd

    - Edit the following file:

    # vi /etc/snmp/snmpd.conf

        Comment the line (ADD '#' in front):

    com2sec paranoid  default         public
        
        And UNcomment the line (REMOVE the '#' in front):

    #com2sec readonly  default         public

        Edit the file /etc/default/snmpd, and find the line:
    
SNMPDOPTS='-Lsd -Lf /dev/null -u snmp -I -smux -p /var/run/snmpd.pid 127.0.0.1'

        Remove 127.0.0.1 at the end, so you have:

SNMPDOPTS='-Lsd -Lf /dev/null -u snmp -I -smux -p /var/run/snmpd.pid'

    - Restart snmpd

    # /etc/init.d/snmpd stop
    # /etc/init.d/snmpd start


4. Check that snmpd is working:

    # snmpstatus -c public -v1 localhost

    - What do you observe ?

5. Check now that you can run snmpstatus against your neighbor's server:

    - Find out what your neighbor's IP is, ask them to run:

    # ifconfig eth0

    (your IP is 169.223.5.X where X is between 10-24)

    - Check snmp against their machine:

    # snmpstatus -c public -v1 169.223.5.X

6. Adding MIBs

    Remember when you ran:

    # snmpwalk -c san0g -v1 169.223.1.1 1.3.6.1.4.1.9.9.13.1.3 | more

    If you noticed, the SNMP client (snmpwalk) couldn't interpret
    all the OIDs coming back from the Agent:

        SNMPv2-SMI::enterprises.9.9.13.1.3.1.3.1 = Gauge32: 27
        SNMPv2-SMI::enterprises.9.9.13.1.3.1.3.2 = Gauge32: 41
        SNMPv2-SMI::enterprises.9.9.13.1.3.1.3.3 = Gauge32: 26

    What is '9.9.13.1.3.1.3' ?

    To be able to interpret this information, we need to download extra
    mibs...

    - Download the following files to your machine:

    # cd /usr/share/snmp/mibs
    # wget ftp://ftp.cisco.com/pub/mibs/v2/CISCO-SMI.my 
    # wget ftp://ftp.cisco.com/pub/mibs/v2/CISCO-ENVMON-MIB.my

    - Create the file /usr/share/snmp/snmp.conf, and put into it:

        mibdirs /usr/share/snmp/mibs

        mibs ALL
    
    Save the file, quit.

    Now, try again:

    # snmpwalk -c san0g -v1 169.223.5.253 1.3.6.1.4.1.9.9.13.1.3 | more