System information
Introduction to Switched Observer
307
and switches from lower-end manufacturers do not offer any management options
whatsoever.
If your switch does not offer any management options, Observer (or any
protocol analyzer for that matter) will be of little use in your switched
environment.
Should your switch fall into the first category, there are typically four different types of
management options available:
1. An SNMP agent to monitor different switch traffic and device-specific information.
2. An internal RMON Probe to provide partial or full RMON statistics and capture
functions within the hardware of the switch.
3. The ability to mirror ports (e.g., spanning ports [Cisco’s term], tap port, or
management ports).
4. A Web-based management console providing various users and port-based statistics.
Observer provides analysis and management functionality for the first three options. Your
Web browser provides access for the last.
Switch SNMP Agents
For switches that include an SNMP agent in the switch hardware, Observer’s SNMP
Management Console will allow you to query and view any or all SNMP data that the
switch collects. SNMP offers a number of advantages and disadvantages over standard
protocol analyzers. In general, protocol analysis and SNMP are considered a
complementary solution—which is to say that their feature sets have little overlap.
Additionally, SNMP is not often considered a reliable form of problem management
because it is not an independent view of the situation. A good example would be when
you’re having a problem with your router—do you really want to take your router’s view
of the situation? SNMP used for problem determination provides information from the
source of the problem at the exact time when that information is most likely to be
unreliable. SNMP management is better suited for management, rather than
troubleshooting.
SNMP management can provide device-specific information that a protocol analyzer
cannot “see” from within the device. Examples of this would be internal switch
forwarding time-outs, switch management passwords, serial number, and ID information.
Internal RMON Probes
A number of switches offer some or all of the RMON1/2 statistics to use in managing and
troubleshooting your switch and the associated devices on the ports.
In this environment, should the RMON implementation be sufficient for real work,
Observer’s RMON(2) Extension may be used to query, configure, and report any and all
of the 19 RMON1/2 groups of information.