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.
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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 AggreGate 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 alloted 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 AggreGate 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 |
Packet Data Size (see also Ping Properties) |
Check whether the host properly answers to Ping (ICMP echo) requests. |
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SNMP |
Protocol Port SNMP Protocol Version Read Community Maximum PDU Size Security Level Username Authentication Protocol Authentication Password Privacy (Encryption) Protocol Privacy (Encryption) Password (see also SNMP Connection Properties) |
Check whether SNMP agent is running on the host. This is performed by sending SNMP GETNEXT request (considering the options provided). If the device responds with a correct SNMP value, the service is considered "alive". |
TCP Services |
Port Timeout (see also TCP Service Properties) |
Check whether device listens the specified TCP ports by attempting to establish a TCP connection within a given Timeout. Only ports that AggreGate 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 Services |
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 AggreGate Network Manager has received any reply to its datagram. Only ports that AggreGate 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) |
Check 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) |
Check if the device accepts FTP connection at the port specified. |
DNS |
Port Protocol (see also DNS Properties) |
Check 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) |
Check 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) |
Check 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) |
Check 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) |
Check whether the device replies to DHCP requests. AggreGate 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) |
Check 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) |
Check 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) |
Check 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. AggreGate Network Manager tries to find a service using each variant specified.
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The server stops iterating serice 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.