Network Discovery properties

The following properties control how Network Discovery works.

The default values are correct for most discoveries. Navigate to Discovery Definitions > Properties to edit the properties.
Table 1. Network Discovery Properties
Property Description Default
BGP Router Exploration Disable Controls whether Network Discovery exploration of routers running the BGP protocol is disabled. Normally such exploration is disabled, because of the huge size of BGP routing tables, and because such routers typically operate at the edge of large networks where further network discovery would be irrelevant. The only time this value should be set to no is in the unlikely case that your organization uses BGP routers as edge routers between relatively small networks, such as between buildings on a single campus. Yes
Maximum Netmask Size for Discoverable Networks (bits) The maximum number of bits in a regular netmask for networks that are discovered by Network Discovery. By regular netmask, we mean a netmask that can be expressed in binary as a string of ones followed by a string of zeroes. For example, 255.255.255.0 is regular, and 255.255.255.64 is irregular. Regular networks are commonly expressed like this: 10.0.0.0/24, which means a network address of 10.0.0.0 with a netmask of 255.255.255.0. Larger bit numbers mean networks with smaller numbers of addresses in them. For example, the network 10.128.0.128/30 has four addresses in it: one network address (10.128.0.128), one broadcast address (10.128.0.131), and two usable addresses (10.128.0.129 and 10.128.0.130). Small networks like this are commonly configured in network gear to provide loopback addresses or networks used strictly by point-to-point connections. Since these sorts of networks generally do not need to be discovered by Network Discovery, it would be useful to filter them out. By setting this property to a value of 1 through 32, you can limit the sizes of regular networks that are discovered. Setting it to any other value causes all networks to be discovered. Irregular networks are always discovered. The default value is 28, which means that regular networks with 8 or fewer addresses are not discovered. 28
Network Router Selection Method This property controls the method used to decide which router should be selected as the router to be associated with a given IP Network. The possible values are: First Router (the first router that discovers the network is associated), Last Router (the last router that discovers the network is associated), Most Networks (the router with the most attached networks is associated), and Least Networks (the router with the least attached networks is associated). Most Networks
Physical Interface Types A comma-separated list of interface types that should be considered physical for the purposes of network discovery. In other words, if a router (or device capable of routing) has an interface of this type, the networks connected to that interface is considered locally connected to that device. The default interface types include Ethernet, 802.11, and Token Ring types. Interface type numbers are defined in the SNMP MIB-2, specifically in OID 1.3.6.1.2.1.2.2.1.3. 6,117,9,71,209
Switch Interface Types Comma-separated list of interface types that is considered. Interface type numbers are defined in the SNMP MIB-2, specifically in OID 1.3.6.1.2.1.2.2.1.3. Devices with any interface types that do not appear in this list are classified as routers, if they have routing. A complete list of the interface type numbers may be found on the IANA web site, in the list of ifType-MIB Definitions. 7,8,9,26,53,62,69,71,78,115,117,209
Stale Network Discovery Threshold (Days) The number of days until discovered information about network gear is considered stale. While performing network discovery, if a router or other device capable of routing has not been discovered, or if the discovered information is stale, then network discovery launches probes to freshen the information. Otherwise, it reuses the information that has already been discovered. If this number is negative, then any previously discovered information is always considered stale, and network discovery always launches probes to freshen the information. -1
Network Discovery Debugging Enables extensive logging (for debugging purposes) of all network Discovery activities on the instance. Normally this is only set to yes by developers. Yes