LevelOne FGL-2870 - Manual (Page 119)

Sampling Traffic Flows
3-65
3
CLI – Use the snmp-server view command to configure a new view. This example
view includes the MIB-2 interfaces table, and the wildcard mask selects all index
entries.
Sampling Traffic Flows
The flow sampling (sFlow) feature embedded on this switch, together with a remote
sFlow Collector, can provide network administrators with an accurate, detailed and
real-time overview of the types and levels of traffic present on their network. The
sFlow Agent samples 1 out of n packets from all data traversing the switch,
re-encapsulates the samples as sFlow datagrams and transmits them to the sFlow
Collector. This sampling occurs at the internal hardware level where all traffic is
seen, whereas traditional probes will only have a partial view of traffic as it is
sampled at the monitored interface. Moreover, the processor and memory load
imposed by the sFlow agent is minimal since local analysis does not take place. The
wire-speed transmission characteristic of the switch is thus preserved even at high
traffic levels.
As the Collector receives streams from the various sFlow agents (other switches or
routers) throughout the network, a timely, network-wide picture of utilization and
traffic flows is created. Analysis of the sFlow stream(s) can reveal trends and
information that can be leveraged in the following ways:
• Detecting, diagnosing, and fixing network problems
• Real-time congestion management
• Understanding application mix (P2P, Web, DNS, etc.) and changes
• Identification and tracing of unauthorized network activity
• Usage accounting
• Trending and capacity planning
Console(config)#snmp-server view ifEntry.a
1.3.6.1.2.1.2.2.1.1.* included 4-96
Console(config)#exit
Console#show snmp view
4-97
View Name: ifEntry.a
Subtree OID: 1.3.6.1.2.1.2.2.1.1.*
View Type: included
Storage Type: nonvolatile
Row Status: active
View Name: readaccess
Subtree OID: 1.3.6.1.2
View Type: included
Storage Type: nonvolatile
Row Status: active
View Name: defaultview
Subtree OID: 1
View Type: included
Storage Type: nonvolatile
Row Status: active
Console#