
The other option to control the reach of the discoveries is to congure the multicast request to span a certain
number of routers (Congure the General Settings for Device Discoveries on page 64). Spanning routers will
require the routers to be congured to allow multicast request to be forwarded.
The discovery could also be aected by the conguration of your local rewall (Discovering Devices with
HP Web Jetadmin through Firewalls on page 136).
If the router is congured to pass multicast requests on to other sections of the network, and Discovery is
congured to cross multiple routers, then a discovery could potentially discover devices across multiple subnets
and perhaps your entire network.
Details About Running an SLP Multicast Discovery
(For network device discoveries only.)
If one of the discovery methods you choose is SLP multicast (while creating templates (Create Discovery
Templates on page 166), editing templates (Edit Discovery Templates on page 168), or scheduling (Schedule
Discoveries on page 163)), then the Choose SLP multicast settings page is displayed. On this page, select the
number of routers to cross (or hops) for the discovery. Increasing the number of hops might increase the amount
of time for the discovery to complete; plus, it generates more network trac than a discovery with fewer routers
to cross.
HP Web Jetadmin does not add devices that cannot be resolved and managed via SNMP, which might be due to
insucient credentials, to the device list. HP Web Jetadmin enforces device manageability through SNMP before
adding devices to the device list.
IP Broadcast Discovery
IP Broadcast discoveries send SNMP query packets (in the form of IP broadcasts) to one or more IP network(s).
These are used in both PC-Connected and network device discoveries.
IP Broadcast Discoveries for Network Devices
An IP Broadcast discovery enables you to nd devices or HP Web Jetadmin installations when IP broadcast
addressees are known. IP broadcast discoveries send SNMP query packets (in the form of IP broadcasts) to one
or more IP network(s). One network-specic broadcast address exists for each IP subnet on an IP intranet. IP
subnets are determined by the IP network number and the IP subnet mask. IP calculators, available free on the
Internet, are a great way to determine IP broadcast addresses. An all 1s IP broadcast can also be used to query
the entire intranet. Broadcasting is typically blocked by routers due to trac spike concerns.
Characteristics of IP broadcast discoveries for network devices include:
●
Sends SNMP queries over one or more IP broadcasts.
●
Listens for replies and then qualies network connected devices.
●
Default broadcast is the Global Broadcast Address (255.255.255.255).
●
Can use one or more known IP broadcast addresses with optional address descriptions.
●
Limited checking is performed to determine if the broadcast address is valid.
●
Fast and thorough, especially on a local segment.
●
Most modern networks block broadcast trac.
ENWW Discovery 141
Comentarios a estos manuales