Domain 3.1 Flashcards
What are some major performance indicators
Temperature
CPU Usage
Memory
What are some ways to gather bandwidth utilization
SNMAP
Netflow
Sflow
What is latency
The delay between request and the response
What is jitter
The time between frames
Excessive jitter causes you to miss information and can lead to choppy calls.
What are some things that can be watched via the interface
Link status
Error rate
Utilization
Packet drops
Interface resets
Speed and duplex
What is a MIB and what is it used for?
Management Information Database - Used along with SNMP
Database contains OID (Object identifiers)
True or false:
There are three versions of SNMP
SNMP v.1
- Original structured table sent in the clear.
SNMP v.2
- Updated with data enhancements, bulk transfers sent in the clear.
SNMP v.3
- New standard that include encryption, authentication, and message integrity.
True or False:
SNMP can be identified by name or number
Correct, the number format looks like this:
.1.3.6.1.2.1.11.29.0
Each number corresponds to a different piece of information
True or False:
Every Variable in the MIB has a corresponding OID
True:
Some OIDs are common across devices
SNMP makes information requests based off OID, which will be consistent across devices
What port does SNMP operation over for standard SNMP and Trap
SNMP UDP/161
TRAP UDP/162
Describe how SNMP traps work
Thresholds can be set on a target device. SNMP Trap will then send information unsolicited to the central monitoring station
How are audit logs different than standard logs?
They are often much more detailed and specific than standard OS logs
What is syslog used for?
Used for uniform message logging
What are some common syslog severity levels?
Low - Debug messages
High - critical and alert
What are some common interface errors for switches?
Runts
Giants
CRC errors
Encapsulation errors
Describe a Runt and a Giant
Runt - Frames that are less than 64 Bytes ( possible result of collisions)
Giant - frames larger than the standard 1518 bytes
What is a CRC error
They alert that a Frame Check Sequence has failed.
This may indicate a bad cable, or damaged interface
What is an encapsulation error
This will occur when there is an inconsistent configuration between switches connected with a 802.1Q or ISL trunk
What are some common environmental sensors
Humidity level
Electrical - Device and circuit load
Flooding
What does NetFlow accomplish?
Standardized collection method that has many implementations
Gathers traffic statistics from all traffic flows - It will report on shared communications between devices
What are the two components to NetFlow?
The probe and Collector
Probe watches net coms
summary records are sent to the collector