IP-based forwarding of bridged and routed IP packets and unicast ARP

A network device for receiving an address resolution protocol (ARP) request packet from a source host connected to an IP network and forwarding the ARP request packet to a destination host connected to the IP network, said network device comprising:

• machine-readable instructions for:
• receiving the ARP request packet from the source host connected to said network device;
• identifying an IP address of the destination host designated the ARP request packet;
• determining a location on the IP network where the destination host designated by the ARP request packet is connected, without reference to a media access control (MAC) address of the destination host specified in the ARP request packet received from the source host, via look-up of a destination IP address in a list of location-identification information locally stored in a database on the network device;
• and
• forwarding the ARP request packet to another network device without broadcasting the ARP request packet on the IP network and without referencing the MAC address of the destination host specified in the ARP request packet received from the source host;
• and
• circuit logic and/or a processor configured to execute the instructions, wherein,
• the database is distributed across multiple network devices including the network device and another network device,
• the location on the IP network is determined from the database after forwarding the ARP request packet to the another network device,
• the IP network comprises a leaf-spine network fabric,
• the network device is a leaf network device in the leaf-spine network fabric which is an initial network device encountered by the ARP request packet when it reaches the IP network after it issues from the source host,
• the location-identification information comprises a list matching one or more host IP addresses with one or more locations on the IP network where one or more hosts are connected, and
• the location on the IP network is determined from the list.

An IP network comprising:

• a first set of multiple network devices for connecting multiple hosts to the IP network;
• and
• a second set of multiple network devices for connecting together the first set of multiple network devices;
• wherein each network device in the first set of multiple network devices comprises logic for:
• receiving an address resolution protocol (ARP) request packet from a source host connected to said network device;
• identifying an IP address of a destination host designated in the ARP request packet;
• determining a location on the IP network where the destination host designated by the ARP request packet is connected, without broadcasting the ARP request packet on the IP network and without referencing a media access control (MAC) address of the destination host specified in the ARP request packet received from the source host, via look-up of a destination IP address in a first list of location-identification information locally stored in a database;
• labeling the ARP request packet with the location, wherein the location includes a second MAC address;
• and
• forwarding the ARP request packet to another network device in the second set of multiple network devices when the location is not the same network device having received the ARP request packet via the logic;
• and
• wherein,
• each network device in the second set of multiple network devices comprises logic for:
• receiving the ARP request packet from the first set of multiple network devices;
• and
• forwarding the ARP request packet to the first set of multiple network devices which is the location of the destination host on the IP network,
• the database is distributed across multiple network devices including the network device and another network device,
• the location on the IP network is determined from the database after forwarding the ARP request packet to the another network device,
• the IP network comprises a leaf-spine network fabric,
• the network device is a leaf network device in the leaf-spine network fabric which is an initial network device encountered by the ARP request packet when it reaches the IP network after it issues from the source host,
• the location-identification information comprises a list matching one or more host IP addresses with one or more locations on the IP network where the hosts are connected, and
• the location on the IP network is determined from the list.