The Device Hints tab provides hints to NetMRI's discovery engine for locating specific types of network devices (for discovery purposes, chiefly routers and switch-routers) by using IP address patterns and DNS name patterns. For instance, if most routers are found at an IP address ending with ".1", specifying "*.*.*.1" and associating the Router device type for an IP address hint allows the appliance to prioritize discovered devices matching that hint higher in its credential collection queue to help speed discovery. NetMRI considers this hint when it attempts to determine a device type for a discovered device.

• Use a single asterisk (*) to wildcard an entire IPv4 octet (192.168.1.*). The " * " wildcard is not applicable for IPv6 hint rules. The double colon ("::") is used for IPv6 hint values.
• Valid IP address patterns are either the numeric values of the octet or an asterisk for any number of octets in the IP address. For device name matches, valid DNS characters and the asterisk character are valid definitions. For instance, rtr will match any device name with "rtr" in its definition.
• Device hints are optional and are used only to speed network discovery and to assist with the determination of device types absent other discovery data.

To create a new router hint, perform the following:

1. Click the Settings icon > Setup > Discovery Settings > Device Hints, and then click New.
2. Select the Device Type from the dropdown list. Typically, this should be Router or Switch-Router.
3. Enter the IP address pattern or DNS pattern needed for device detection.
4. Click Add to place the new hint into the table.

Device Hints apply across the entire system and are not associated with network views.

IPv6 Hint Details

For IPv6, router hints are formatted to start with a double-colon designator ("::") and followed by the host-side identifier for the hint. IPv6 router rules can be up to 48 bits in length, applying only to networks where the rule fits. The shorter the hint, the broader the rule.

Such rules apply to Router or Switch-Router devices to be used during discovery.

For IPv6 networks, the process entails discovering routes and then sending probes, using those hints, into those networks to discover the intermediate hops leading to them. Discovery performance can be improved if a site uses static IPv6 addresses for routers, such as

<any 64-bit network prefix>:<first 56 bits of host IP>:10

These values can be added as hints. Further examples are as follows: