Category
Ethernet & L2
MAC addresses, OUI lookups, VLAN tags, EtherTypes, and other layer 2 helpers.
Ethernet Frame Size Calculator
Compute Ethernet II frame size, padding, on-the-wire size, overhead and efficiency from a payload size (or the reverse), with VLAN tags and an optional line rate.
EtherType Lookup
Curated reference table and search for common EtherType values: IPv4, IPv6, ARP, VLAN, MPLS, PPPoE and other layer 2 protocols.
MAC Address Formatter
Reformat and analyze MAC addresses: colon/hyphen/dot/bare styles, 48-bit integer, bit-level analysis, U/L and I/G flags, variants.
Multicast MAC Address Mapper
Map an IPv4 (224.0.0.0/4) or IPv6 (ff00::/8) multicast address to its Ethernet multicast MAC, and reverse a multicast MAC to every IP group it could carry.
STP Bridge ID Encoder / Decoder
Encode and decode an 802.1D / 802.1t Spanning Tree Bridge ID: priority field, 4-bit priority, 12-bit extended system ID, and bridge MAC — with a root-election comparison.
VLAN Tag Encoder / Decoder
Encode and decode an IEEE 802.1Q VLAN tag and 802.1ad (QinQ) double tags: TPID, PCP, DEI, VID, and the 16-bit TCI.