Service Selection and Setup

Answering "What to discover?" question, the Service Selection and Setup step specifies a list of services to detect along with parameters to be used for detecting service availability.

Ping Service is the only mandatory service to be checked during discovery, as it is used to determine if a host at specific address is alive (online) during scanning procedure. Other services Iotellect Network Manager are optional.

Service parameters are comprised of the following fields:

  • Discover flag denotes service as taking part in discovery (checked) or excluded (unchecked).
  • Timeout specifies a period of time allotted for a single attempt to detect the service during scanning.
  • Retries sets a number of attempts to detect the service as available.
  • Service-Specific Options defines service detection parameters used by scan procedure.

The following table provides a list of services Iotellect Network Manager is able to discover, along with associated service-specific options and a short description of discovery procedure.

Service Name

Discovery Options

Discovering Activity

Ping

Packet Data Size

(see also Ping Properties)

Check whether the host properly answers to Ping (ICMP echo) requests.

SNMP

Protocol

Port

SNMP Protocol Version

Read Community

Protocol

Maximum PDU Size

Initial OID

Filter OID

Use multi-variable requests to read tables

Security Level

Username

Authentication Protocol

Authentication Password

Privacy (Encryption) Protocol

Privacy (Encryption) Password

(see also SNMP Connection Properties)

Checks whether SNMP agent is running on the host. This is performed by sending SNMP GETNEXT request with the Initial OID as parameters.

When the Filter OID is specified, the service is considered "alive" only if the device responds with a correct SNMP value and its OID is under the Filter OID's subtree; otherwise, a correct response from the device is enough to deem its SNMP service alive.

TCP

Port

Timeout

(see also TCP Service Properties)

Checks whether device listens the specified TCP ports by attempting to establish a TCP connection within a given Timeout.

Only ports that Iotellect Network Manager has successfully connected to will be configured for future monitoring.

The Discovery Timeout setting is ignored by this service. No data is send to the host during discovery.

UDP

Port

Timeout

Data To Send

(see also UDP Service Properties)

Check whether the host replies when user-defined data is sent to its remote port as an UDP datagram. The port is considered "available" if Iotellect Network Manager has received any reply to its datagram.

Only ports that Iotellect Network Manager has received replies from will be configured for future monitoring.

The Discovery Timeout setting is ignored by this service.

HTTP

Port

URL

Request Type

(see also HTTP Properties)

Checks whether a web server is available on the given Port by sending GET or POST request with the specified URL to the remote host and reading the reply.

FTP

Port

(see also FTP Properties)

Checks if the device accepts FTP connection at the port specified.

DNS

Port

Protocol

(see also DNS Properties)

Checks whether the device answers to a predefined DNS lookup request sent to the Port via the specified Protocol (UDP or TCP). If the device correctly answers the request, we deem DNS service "alive".

IMAP

Port

(see also IMAP Properties)

Checks whether the device accepts a connection at the specified Port and replies with some data. If the connection is successfully established and a non-empty reply is received, the service is deemed as "alive".

POP3

Port

(see also POP3 Properties)

Checks whether the device accepts a connection at the specified Port. If the connection is successfully established and a non-empty reply is received, we consider the service to be "alive".

SMTP

Port

(see also SMTP Properties)

Checks whether the device correctly answers HELO command of Simple Mail Transfer Protocol (according to RFC 821). If the device responds with OK reply (reply code 250), SMTP service is considered available.

SSH

Port

(see also SSH Properties)

Check whether the device accepts an SSH connection (via SSH-2 protocol) at the specified Port. If the connection can be established, the service is deemed as "alive".

DHCP

MAC Address

(see also DHCP Properties)

Checks whether the device replies to DHCP requests. Iotellect Network Manager sends a DHCP discovery request and waits for a reply. If the reply is received within the discovery timeout period, the service is denoted as available.

LDAP

Port

Username

Password

(see also LDAP Properties)

Checks whether the device accepts LDAP connections with the specified parameters. We deem LDAP service "alive", if the connection was successfully established and LDAP auth didn't fail.

Radius

Authentication Port

Username

Password

Radius Secret

(see also Radius Properties)

Checks whether the device accepts Radius authenticate requests. If the device returns an Access Accept (see RFC 2138) response, the service is considered available.

WMI

Domain

Username

Password

Namespace

(see also WMI device driver)

Checks whether the device accepts WMI connections.

Parameter Variants

All the services excluding TCP Services, UDP Services and Ping, support multiple parameter variants to be used during scanning. The variants are provided as multiple records in service discovery options table. Iotellect Network Manager tries to find a service using each variant specified.

The server stops iterating service parameter variants when the first "working" variant is found.

Centralized Storage of Discovery Options

When a new discovery process is started, all service discovery options are loaded from the Network Device Discovery Plugin global configuration.

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