Information Technology Reference
In-Depth Information
Defined by RFC 2021, RMON2 extends the RMON group with the MIB groups listed in
Ta ble 1 5 - 6 .
Ta b l e 1 5 - 6
RMON2 Groups
ID
Name
Description
11
Protocol Directory
Lists the protocols the device supports
12
Protocol Distribution
Traffic stat ist ic s for each protocol
13
Address Mapping
Contains network-to-MAC layer address mapping (IP to MAC)
14
Network Layer Host
Contains statistics for traffic sent to or from network layer hosts
15
Network Layer
Matrix
Contains statistics for conversations between two network layer
hosts
16
Application Layer
Host
Contains application layer statistics for traffic sent to or from
each host
17
Application Layer
Matrix
Contains application layer statistics for conversations between
pairs of hosts
18
User History
Contains periodic samples of specified variables
19
Probe Configuration
Probes parameter configuration
NetFlow
Cisco NetFlow allows the tracking of IP flows as they are passed through routers and mul-
tilayer switches. IP flows are a set of IP packets within a specific timeslot that share a
number of properties, such as the same source address, destination address, type of serv-
ice, and protocol number. NetFlow information is forwarded to a network data analyzer,
network planning tools, RMON applications, or accounting and billing applications. Net-
Flow allows for network planning, traffic engineering, billing, accounting, and application
monitoring. The most recent version of NetFlow is NetFlow Version 9, which is defined in
RFC 3954. NetFlow consists of three major components:
Key
To p i c
NetFlow accounting:
Collects IP data flows entering router or switch interfaces and
prepares data for export. It enables the accumulation of data on flows with unique
characteristics, such as IP addresses, application, and class of service (CoS).
■
Flow collector engines:
Captures exported data from multiple routers and filters
and aggregates the data according to customer policies, and then stores this summa-
rized or aggregated data.
■
Network data analyzers:
Displays a graphical user interface (GUI) and analyzes
NetFlow data collected from flow collector files. This allows users to complete near-
real-time visualization or trending analysis of recorded and aggregated flow data.
Users can specify the router and aggregation scheme and desired time interval.
■
devices aggregate data and export the information. Each unidirectional network flow is
