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7.10 Measuring Host Statistics with RMON

To diagnose many network problems, it is necessary to look beyond the overall health of the network and focus on the operation of individual devices. The RMON hosts, hostTopN, and matrix groups are designed for those purposes: they look at host operation, hosts whose operation tops a list of particular statistics, and a matrix of host-to-host communication, respectively. In this example, we will use the capabilities of RMON to look at some host-specific characteristics, and then we’ll zoom in on one particular host to discover its communications characteristics (see Figure 7-10).


Figure 7-10.  Gathering host statistics

A summary of the network operation shows a variety of RMON activities (Trace 7.10a). Note that Frames 1–2 are accessing information from the hostTable, {1.3.6.1.2.1.16.4.2} or {rmon 4.2}; Frames 3–32 are accessing information from the matrixSDTable {1.3.6.1.2.1.16.6.2} or {rmon 6.2}; and Frame 33–52 are accessing information from the matrixDSTable, {1.3.6.1.2.16.6.3 } or {rmon 6.3}. (As a review, the hostTable contains statistical data about a particular host; the matrixSDTable contains statistics for a particular conversation between two addresses, indexed by source and destination MAC addresses; and the matrixDSTable contains statistics for a particular conversation between two addresses, but this time, indexed by destination and source MAC addresses.)

Trace 7.10a. RMON host information (summary)

  Sniffer Network Analyzer data from 25-Feb at 17:24:44,
   file TOPNIPCN.ENC, Page 1

  SUMMARY    Delta T    Destination    Source    Summary
  M  1                  Probe          Manager   SNMP Get
                                                   rmon.4.2.1.1.20480…
     2       0.0032     Manager        Probe     SNMP GetReply
                                                   rmon.4.2.1.1.20480…
     3       0.0052     Probe          Manager   SNMP GetNext
                                                   rmon.6.2.1.1.20480…
     4       0.0032     Manager        Probe     SNMP GetReply
                                                   rmon.6.2.1.1.20480…
     5       0.0049     Probe          Manager   SNMP GetNext
                                                   rmon.6.2.1.1.20480…
     6       0.0031     Manager        Probe     SNMP GetReply
                                                   rmon.6.2.1.1.20480…
     7       0.0047     Probe          Manager   SNMP GetNext
                                                   rmon.6.2.1.1.20480…
     8       0.0031     Manager        Probe     SNMP GetReply
                                                   rmon.6.2.1.1.20480…
     9       0.0046     Probe          Manager   SNMP GetNext
                                                   rmon.6.2.1.1.20480…
    10       0.0032     Manager        Probe     SNMP GetReply
                                                   rmon.6.2.1.1.20480…
    11       0.0047     Probe          Manager   SNMP GetNext
                                                   rmon.6.2.1.1.20480…
    12       0.0031     Manager        Probe     SNMP GetReply
                                                   rmon.6.2.1.1.20480…
    13       0.0048     Probe          Manager   SNMP GetNext
                                                   rmon.6.2.1.1.20480…
    14       0.0030     Manager        Probe     SNMP GetReply
                                                   rmon.6.2.1.1.20480…
    15       0.0047     Probe          Manager   SNMP GetNext
                                                   rmon.6.2.1.1.20480…
    16       0.0031     Manager        Probe     SNMP GetReply
                                                   rmon.6.2.1.1.20480…
    17       0.0046     Probe          Manager   SNMP GetNext
                                                   rmon.6.2.1.1.20480…
    18       0.0032     Manager        Probe     SNMP GetReply
                                                   rmon.6.2.1.1.20480…
    19       0.0048     Probe          Manager   SNMP GetNext
                                                   rmon.6.2.1.1.20480…
    20       0.0031     Manager        Probe     SNMP GetReply
                                                   rmon.6.2.1.1.20480…
    21       0.0047     Probe          Manager   SNMP GetNext
                                                   rmon.6.2.1.1.20480…
    22       0.0031     Manager        Probe     SNMP GetReply
                                                   rmon.6.2.1.1.20480…
    23       0.0049     Probe          Manager   SNMP GetNext
                                                   rmon.6.2.1.1.20480…
    24       0.0030     Manager        Probe     SNMP GetReply
                                                   rmon.6.2.1.1.20480…
    25       0.0047     Probe          Manager   SNMP GetNext
                                                   rmon.6.2.1.1.20480…
    26       0.0031     Manager        Probe     SNMP GetReply
                                                   rmon.6.2.1.1.20480…
    27       0.0047     Probe          Manager   SNMP GetNext
                                                   rmon.6.2.1.1.20480…
    28       0.0031     Manager        Probe     SNMP GetReply
                                                   rmon.6.2.1.1.20480.
    29       0.0048     Probe          Manager   SNMP GetNext
                                                   rmon.6.2.1.1.20480…
    30       0.0030     Manager        Probe     SNMP GetReply
                                                   rmon.6.2.1.1.20480…
    31       0.0048     Probe          Manager   SNMP GetNext
                                                   rmon.6.2.1.1.20480.
    32       0.0030     Manager        Probe     SNMP GetReply
                                                   rmon.6.2.1.1.20480…
    33       0.0048     Probe          Manager   SNMP GetNext
                                                   rmon.6.3.1.1.20480…
    34       0.0030     Manager        Probe     SNMP GetReply
                                                   rmon.6.3.1.1.20480…
    35       0.0047     Probe          Manager   SNMP GetNext
                                                   rmon.6.3.1.1.20480…
    36       0.0031     Manager        Probe     SNMP GetReply
                                                   rmon.6.3.1.1.20480…
    37       0.0046     Probe          Manager   SNMP GetNext
                                                   rmon.6.3.1.1.20480…
    38       0.0032     Manager        Probe     SNMP GetReply
                                                   rmon.6.3.1.1.20480…
    39       0.0047     Probe          Manager   SNMP GetNext
                                                   rmon.6.3.1.1.20480…
    40       0.0031     Manager        Probe     SNMP GetReply
                                                   rmon.6.3.1.1.20480…
    41       0.0047     Probe          Manager   SNMP GetNext
                                                   rmon.6.3.1.1.20480…
    42       0.0031     Manager        Probe     SNMP GetReply
                                                   rmon.6.3.1.1.20480…
    43       0.0046     Probe          Manager   SNMP GetNext
                                                   rmon.6.3.1.1.20480…
    44       0.0032     Manager        Probe     SNMP GetReply
                                                   rmon.6.3.1.1.20480…
    45       0.0047     Probe          Manager   SNMP GetNext
                                                   rmon.6.3.1.1.20480…
    46       0.0031     Manager        Probe     SNMP GetReply
                                                   rmon.6.3.1.1.20480…
    47       0.0047     Probe          Manager   SNMP GetNext
                                                   rmon.6.3.1.1.20480…
    48       0.0031     Manager        Probe     SNMP GetReply
                                                   rmon.6.3.1.1.20480..
    49       0.0049     Probe          Manager   SNMP GetNext
                                                   mon.6.3.1.1.20480…
    50       0.0032     Manager        Probe     SNMP GetReply
                                                   rmon.6.3.1.1.20480…
    51       0.0048     Probe          Manager   SNMP GetNext
                                                   rmon.6.3.1.1.20480…
    52       0.0031     Manager        Probe     SNMP GetReply
                                                   rmon.6.3.1.1.20480…


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