Recipe 3.5 Logging Client MAC Addresses

Problem

You want to record the MAC (hardware) address of clients that access your server.

Solution

This cannot be logged reliably in most network situations and not by Apache at all.

Discussion

The MAC address is not meaningful except on local area networks (LANs) and is not available in wide-area network transactions. When a network packet goes through a router, such as when leaving a LAN, the router will typically rewrite the MAC address field with the router's hardware address.

See Also

• The TCP/IP protocol specifications (see http://www.rfc-editor.org/cgi-bin/rfcsearch.pl and search for "TCP" in the title field)