MAC address 40:D8:55:03:E details

Assigned Prefix
40:D8:55:03:E

36-bit Prefix (IAB)

Block Base Allocation
40:D8:55:03:E0:00

Hardware Interface 0x000 (Min)

Block Top Boundary
40:D8:55:03:EF:FF

Hardware Interface 0xFFF (Max)

Network Addressing & Host Scope

IAB

This assignment represents an IEEE IAB allocation, granting a dedicated boundary of 4,096 unique host MAC addresses.

START: 40:D8:55:03:E0:00 4,096 Total Addresses END: 40:D8:55:03:EF:FF
Lower Bound (Base Host 0) Upper Bound (Top Boundary)
IEEE Registry Tier IAB Universally Administered (UAA)
Total Host Capacity 4,096 Exact binary space: 212 addresses
Derived IPv6 Link-Local SLAAC Base RFC 4291 EUI-64
fe80::42d8:55ff:fe03:e000

Base address derived from the allocation start, not a network prefix or a verified configured address. The link-local subnet is fe80::/64.

RFC 4291 (Modified EUI-64): This example derives an interface identifier from a 48-bit MAC address by inserting ff:fe and inverting the universal/local bit. An interface can use a different IPv6 identifier.

Octet & Bit Architecture

36-Bit Architecture
Allocation Spread 36-BIT PREFIX (75%) + 12-BIT HOST (25%)
36-Bit Prefix
12-Bit Host
Bit 0 [40:D8:55:03:E]
Bit 36
Bit 47 [Host Top]

OUI / Prefix OUI means Organizationally Unique Identifier. MA-L uses a 24-bit prefix; MA-M and MA-S use 28-bit and 36-bit prefixes.

Host bits The remaining bits define the address space within the allocation.

Binary Octet Breakdown (Prefix)

Colored bits in Octet 0 (the first byte) match the I/G and U/L cards below. Octet indices start at zero.

Octet 0 40 0100 00 0 0
Octet 1 D8 1101 1000
Octet 2 55 0101 0101
Octet 3 03 0000 0011
Octet 4 (high nibble) E_ 1110 [Host]
First octet, bit 1 (U/L) b1 = 0
Universally Administered (UAA)

Globally unique IEEE governed address.

First octet, bit 0 (I/G) b0 = 0
Unicast Transmission

Individual address destination (point-to-point transmission).

Wireshark Dissector Intel
Display Filter: eth.addr[0:4] == 40:d8:55:03 && (eth.addr[4] & 0xf0) == 0xe0
No custom Wireshark manufacturer alias overrides registered for this prefix.

REST API v2

200 OK
CLI curl -s https://api.maclookup.app/v2/macs/40d85503e -H 'Accept: application/json'
{
  "success": true,
  "found": true,
  "macPrefix": "40D85503E",
  "company": "Vishay Celtron Technologies, Inc.",
  "address": "8F, No. 171-1, Sec. 2, Datong Rd., Sijhih City, Taipei  22183, TW",
  "country": "TW",
  "blockStart": "40D85503E000",
  "blockEnd": "40D85503EFFF",
  "blockSize": 4095,
  "blockType": "IAB",
  "updated": "2015-08-29",
  "isRand": false,
  "isPrivate": false
}