Transcript 3 - Terena

AutoDiscovery
Device Attributes Discovery
Ports Discovery
CDP Neighbours Discovery
Layer 3 Hosts Discovery
Introduction
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Reliable monitoring and efficient use depends on the accuracy of the
entered data that describe the network and the network devices.
AutoDiscovery function aims:
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Easing the initial database population
Updating - topology, new devices and relevant data
Discovery on hop-by-hop basis
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Better overview and control over the process
No retrieval of the entire network
Possibility of clear database organisation in the system
• notes
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Location 1
Router 1
Location A
Serial 0
Serial 1
Router A
Serial 1
PC1
PC5
PC2
PC4
PC3
Router A
M
Router B
Router C
Router A1
Router D
Router A2
M
Router A3
Router A3
Location A3
Principles
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AutoDiscovery functions are performed on the Device objects or their
Ports
Data is read and retrieved via SNMP
Result are shown in the Message panel
AutoDiscovery functions perform following actions:
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Attempts to find the discovered Devices in the database
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Device already exists in the database -> update of the object properties
and Links
Device does not exist in the database -> Device is created in the Discovered
Folder, located underneath the Device on which the AutoDiscovery service
was initialised.
Links are being set to the discovered Devices/Ports, depending on the
type of initialized AutoDiscovery function.
Device Attributes Discovery
Setting the Name information for every SNMP
enabled device
• For Cisco Systems devices, finds serial number and
model information
• Plans for the future…
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Deeper and intelligent analysis
Discovering type of the device and manufacturer
Discovering device attributes (type of hardware, type of
OS, memory and storage size…)
Ports Discovery
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Discovers all network interfaces (ports) with following attributes:
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short and full name of the port
description of the port
bandwidth
SNMP ID
Port objects are updated or created under the Device in the
information system hierarchy and each Port is linked to the parent
Device
SNMP ID – index to member in OID list - the most important port
attribute
Optional selection of automatic PortDiscovery function on the Devices
on daily basis
Persistent interface indexes
CDP Neighbours Discovery
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Based on CDP (Cisco Discovery Protocol)
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Discovering neighbour devices
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Creating the Links between Devices
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CDP offers the information about models of these devices, as well as
connected ports
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The final result is creating Links between two Ports of neighbouring
Devices, which represents the topological connection in this part of
the computer network
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Cisco only up to now - waiting for the Link Layer Discovery Protocol
(LLDP) and MIB…
Layer 3 Hosts Discovery
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Started on routers (Layer 3 device) or router ports
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Discovers all IP address of end devices (hosts) on adhering
local segments (sub-networks)
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Based on ARP table
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NetIIS system gets the address range in the adhering sub-network. This address
range is pinged, in order to refresh the router’s ARP table, from where IP and
MAC addresses of end devices are retrieved
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NetBIOS and DNS names are requested from host devices, which are set in the
Device name
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A new object type Device is created within the Discovered Folder, which
presents the local sub-network, under a name based on the IP address and
length of the mask split with an under score (e.g. 10.1.2.0_24)
AutoDiscovery
Summary
Device Attributes Discovery
Ports Discovery
CDP Neighbours Discovery
Layer 3 Neighbours Discovery