Guide
Annotate a device inventory
An ARP table or DHCP export is an observation. Add registration context without turning it into a claim about device ownership.
Start with the source
An ARP table shows IP-to-link-layer mappings seen by one host or router at a point in time. A DHCP lease export shows addresses a server allocated during lease periods. Neither is a complete inventory of every device on a network. Preserve the source file, observation time and network or VLAN before extracting addresses. A copied command output can contain interface names, IPv4 and IPv6 addresses, duplicate MACs and incomplete lines.
Extract and annotate
- Paste the output or choose a local file in Bulk MAC. The parser accepts complete MAC formats, including colon, hyphen and Cisco dotted forms. It does not remove arbitrary punctuation to guess an address.
- Review the unique-address count and occurrence count. Repeated sightings are useful, but they are not extra devices. Keep the first observed line and compare it with the source if a row looks surprising.
- Download CSV or JSON. The annotation includes the most specific covering IEEE assignment, registry type, country when supplied, and local or group bits. The exported CSV protects spreadsheet cells that begin with formula characters.
- Join the export to your asset register using an authenticated asset ID or a documented lease reference. Keep unknown and local addresses as unknown rather than inventing a vendor.
Read a registrant carefully
IEEE MA-L, MA-M and MA-S blocks can overlap in prefix space; narrower assignments can sit inside a wider one. A lookup should prefer the narrowest covering block. An assignment names the registrant of address space. Hardware makers, resellers, virtual interfaces and private Wi-Fi addressing can make the observed device different from the registrant. The location or country in a record is the registrant field, not the device location.
For mixed logs, Extract can first identify MACs, IPs and other identifiers and compare two lists. For a single questionable row, MAC inspector shows the parse format and assignment caveats. The dataset behind these results is downloadable with checksums, so an offline process can repeat the annotation against the same version.