Specifications

www.linuxjournal.com august 2008 | 73
another, they must have matching community names/strings.
In many deployments, administrators use the default commu-
nity name of public (and/or private), which creates a security
risk. I recommend changing these strings and making them
into a short phrase. You can add numbers and characters to
make the community name more complex to guess/crack, but
I find phrases easier to remember.
Click on the Devices link on the navigation menu on the
left, so that /Devices is listed near the top of the page. Click
on the zProperties tab and scroll down. Enter an SNMP com-
munity string in the zSNMPCommunitiy field. For our test envi-
ronment, I used the string whatsourclearanceclarence. You can
use different strings with different subclasses of systems or
individual systems, but by setting it at the /Devices class, it will
be used for any subclasses unless it is overridden. You also
could list multiple strings in the zSNMPCommunities under the
/Devices class, which allows you to define multiple strings for
the discovery process discussed later. Make sure your commu-
nity string (zSNMPCommunity) is in this list.
Installing Net-SNMP on Linux Clients
Now, let’s set up our Linux systems so they can talk to the
Zenoss server. After installing and configuring the operating
systems on our other Linux servers, install the Net-SNMP
package on each using the following command on the
Ubuntu server:
sudo apt-get install snmpd
And, on the Fedora server use:
yum install net-snmp
Once the Net-SNMP packages are installed, edit out any
other lines in the Access Control sections at the beginning of
the /etc/snmp/snmpd.conf, and add the following lines:
## sec.name source community
com2sec local localhost whatsourclearanceclarence
com2sec mynetwork 192.168.142.0/24 whatsourclearanceclarence
## group.name sec.model sec.name
group MyROGroup v1 local
group MyROGroup v1 mynetwork
group MyROGroup v2c local
group MyROGroup v2c mynetwork
## incl/excl subtree mask
view all included .1 80
## context sec.model sec.level prefix read write notif
access MyROGroup "" any noauth exact all none none
Do not edit out any lines beneath the last Access Control
sections. Please note that the above is only a mildly restrictive
configuration. Consult the snmpd.conf file or the Net-SNMP
documentation if you want to tighten access. On the Ubuntu
server, you also may have to change the following line in the
/etc/snmp/default file to allow SNMP to bind to anything other
than the local loopback address:
SNMPDOPTS='-Lsd -Lf /dev/null -u snmp -I -smux -p /var/run/snmpd.pid'
Installing SNMP on Windows
On the Windows server, access the Add/Remove Programs util-
ity from the Control Panel. Click on the Add/Remove Windows
Components button on the left. Scroll down the list of
Components, check off Management and Monitoring Tools,
and click on the Details button. Check Simple Network
Management Protocol in the list, and click OK to install. Close
the Add/Remove window, and go into the Services console
from Administrative Tools in the Control Panel. Find the
SNMP service in the list, right-click on it, and click on
Properties to bring up the service properties tabs. Click on the
Traps tab, and type in the community name. In the list of Trap
Destinations, add the IP address of the Zenoss server. Now,
click on the Security tab, and check off the Send authentica-
tion trap box, enter the community name, and give it
READ-ONLY rights. Click OK, and restart the service.
Return to the Zenoss management Web page. Click the
Devices link to go into the subclass of /Devices/Servers/Windows,
and on the zProperties tab, enter the name of a domain admin
account and password in the zWinUser and zWinPassword
fields. This account gives Zenoss access to the Windows
Management Instrumentation (WMI) on your Windows systems.
Make sure to click Save at the bottom of the page before
navigating away.
Adding Devices into Zenoss
Now that our systems have SNMP, we can add them into
Zenoss. Devices can be added individually or by scanning the
network. Let’s do both. To add our Ubuntu server into Zenoss,
click on the Add Device link under the Management naviga-
tion section. Enter the IP address of the server and the com-
munity name. Under Device Class Path, set the selection to
/Server/Linux. You could add a variety of other hardware, soft-
ware and Zenoss information on this page before adding a
system, but at a minimum, an IP address name and community
name is required (Figure 1). Click the Add Device button, and
the discovery process runs. When the results are displayed,
click on the link to the new device to access it.
To scan the network for devices, click the Networks link
under Browse By section of the navigation menu. If your
network is not in the list, add it using CIDR notation. Once
added, check the box next to your network and use the drop-
down arrow to click on the Select Discover Devices option.
You will see a similar results page as the one from before.
When complete, click on the links at the bottom of the results
page to access the new devices. Any device found will be
placed in the /Discovered class. Because we should have
discovered the Fedora server and the Windows server,
they should be moved to the /Devices/Servers/Linux and
/Devices/Servers/Windows classes, respectively. This can be
done from each server’s Status tab by using the main drop-down