Lucent Technologies P550 manual 278

Analyzing Network Performance Using RMON and Ethernet Statistics (Layer 2 & Layer 3)

7.Use Table 17-1to interpret the Ethernet Interface statistical values:

Table 17-1.Interpreting Ethernet Interface Statistics

Statistic	Indicates	Actions
Sample	The sample number.	N/A
Interval Start	The date and time this log entry	N/A
	was made.
Utilization	Percentage of utilization.	The percentage of available
		bandwidth used by traffic.
Bytes	Raw number of octets received at	A sharp increase could indicate a
	the interface. Provides some	need to reconfigure the network.
	indication of the amount of
	network bandwidth being used.
Packets	Counts the raw number of readable	A sharp increase could indicate a
	Ethernet packets of legal length	need to reconfigure the network.
	received at the interface.	(However, octets are a better
		indication of bandwidth
		utilization.)
Broadcasts	Broadcast packets are a normal part	Uses monitoring to recognize
	of network operation. For example,	oncoming broadcast storms.
	IP networks use broadcasts as part	Broadcast storms occur when
	of Address Resolution Protocol	stations are creating traffic that
	(ARP) to resolve network	generates more traffic.
	addresses.	Possible cause: Broadcasts cause
		every host on a network segment
		to process the packet.
		Possible actions:
		•	To prevent broadcast storms,
			use VLANs to limit the area of
			the network that each
			broadcast packet affects. In
			general, each VLAN creates a
			separate broadcast domain.
			More VLANs mean less
			proliferation of broadcast
			packets.
		•	Monitor the broadcast rate of
			your network during normal
			operation.
		•	Establish a baseline.
		•	Use Rate Limiting to reduce
			broadcasts.

17-2 Cajun P550/P220 Switch Operation Guide