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NETWORK
MANAGEMENT OR NETWORK MONITORING? |
authored by Chuck
Bolvin, VP of Technology
Do you know what’s going on in your wireless network? Are
all of your access points functioning? Do they all have the correct
settings? Are any of the access points or routing gear having trouble
due to conflicting channels or too much traffic? Are all the access
points at the same firmware revision? Has the RADIUS server service
failed? Do you have a rogue access point strategy?
Would you like to know these things before the
angry phone calls start for users or customers?
Maybe all you need is to know what’s up or down, or
performance versus full-blown configuration and control.
These are important questions for anyone who has
implemented or is responsible for a wireless network. This would apply
to most wired networks as well. And since a wireless network is just
an extension of a wired one, keeping an eye on both at the same time
is really easier than it seems.
Traditional Network Management usually means being able to
grab performance data and errors from a device as well as remotely
configuring the device. These systems can configure access points,
switches, etc from a central station. They also can perform functions
such as remotely changing server parameters, restarting services,
downloading new firmware, etc.
Most Network Management Systems (NMS) use SNMP as the primary
protocol. SNMP has been around for many years and is present in
virtually all enterprise class products including wireless access
points. Most SNMP based NMS systems can support multiple vendors
through a file called a MIB (Management Information Base). The MIB
contains the message formats needed by the NMS system to talk to a
specific vendor’s device. The MIB is loaded into the NMS system and
from that point the NMS system knows how to properly communicate with
that product.
The problem with most full NMS systems though is the cost.
Typical enterprise class NMS systems can cost many thousands of
dollars, usually more than many small businesses can afford. Some
typical examples are CA Unicenter, Tivoli NetView and HP OpenView.
There are other NMS systems that are specific to wireless
LAN’s. These include Wavelink
Mobile Manager, AirWave Management Platform, Cisco
Wireless LAN Solution Engine (WLSE), Symbol SpectrumSoft WNMS and
AdventNet WiFiManager and Colubris' CNMS. A few of these packages are
vendor specific like WLSE and WNMS. But others are multi-vendor like Mobile
Manager, AirWave and Colubris'
CNMS.
Full wireless NMS’ can all perform rogue AP detection and
sometime even rogue AP location and mitigation. Cisco WLSE can detect
rogue AP’s and also disable the switch port it’s connected to in
some configurations. Mobile Manager and AirWave can detect rogue
AP’s but not disable them.
A NMS can require considerable time and effort to get going
mainly due to the considerable capabilities.
Now
let’s talks about network monitoring.
Network
monitoring is really just watching the network. Getting performance
data, checking to see if devices are still there, seeing error
messages from them when they have trouble. Need to restart an AP or
reconfigure it? Sorry, you’ll have to go visit it or use another
method such as the device’s built in web interface.
Network
monitoring systems can tell you if a Windows Server service failed, or
when an AP dropped off the network due to a power failure and came
back up. Monitoring systems also use SNMP but just to grab info or
send alarms (traps). Many times simple monitoring tools use just a
periodic ICMP ping to check if a device is still there.
Many simple network monitoring tools can display a map of the
network similar to a full NMS.
Examples of Network Monitoring systems are
InterMapper and WISPerMapper from Dartware and What’s Up Gold from
Ipswitch. WISPerMapper supports a large number of broadband products
as well as being capable of keeping an eye on Windows Services such as
RADIUS. What’s Up Gold is very capable when it comes to watching
fairly large wired networks. These kinds of packages can be
considerably less expensive than their counterparts and are generally
much easier to get running.
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