Configuration requirements – Brocade Network Advisor IP User Manual v12.1.0 User Manual
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Brocade Network Advisor IP User Manual
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IP discovery overview
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After creating the list of candidate IP addresses, discovery uses multiple threads to probe devices.
You can define how many threads can be used at one time. Threads operate in parallel, so
communication to multiple devices occurs simultaneously. Each thread takes one address from the
list of candidate IP addresses and probes it. The first step in probing is to determine whether the
device is reachable or not. Discovery provides two methods to determine reachability. The first
method uses ICMP ping to probe the device. The second method opens a connection to the IP
address (currently to the Telnet port). This serves as a "ping" to confirm that the IP address is
reachable and some device is listening. By default, if the device responds by either accepting or
rejecting the connection, then the connection is closed and discovery continues.
The next step uses SNMP queries. The first query determines whether the device is a IronWare OS
or Network OS device or not. Discovery rotates through a list of candidate SNMP community strings
until it finds one that works. For devices that already exist in the database, the community string
recorded in the database for that device is tried first.
If you configure discovery to search for neighbor addresses (refer to
discovery profile preferences”
on page 87), the second query scans the device's SNMP ARP table.
Discovery adds any IP address from the ARP table to the list of candidate IP addresses.
Similarly, if you configure discovery to search for neighbor addresses (refer to
advanced discovery profile preferences”
on page 87), the third query scans the device’s SNMP
LLDP, FDP, and CDP tables. Any neighbor IP address is added to the list of candidate IP addresses
to probe. Discovery adds any IP address from the LLDP, FDP, and CDP tables to the list of candidate
IP addresses.
Discovery also tries to determine the host name of the device by requesting the Management
application server operating system to perform various mappings of the device IP addresses to
host names and host names back to IP addresses, using whatever mechanism the operating
system uses (typically Domain Name Server) to determine the host name for a device.
If discovery determines that the device is reachable and manageable, then discovery uses the full
set of SNMP queries to collect asset information from the device. Discovery then adds or updates
the device in the database and sends notification to other applications.
Rediscovery updates can occur using any of the following methods:
•
Lazy polling.
•
Adaptive discovery (triggered by snmp traps).
•
Configuration requirements
Before configuring discovery, obtain the following information:
•
SNMPv1 and SNMPv2c read-write community strings or SNMPv3 read-write credentials for the
devices to be included in discovery. Make sure that devices you want to manage have the
SNMP credentials configured. For more information, refer to
•
Device IP addresses and subnets to probe during discovery. For more information, refer to