VLAN & 802.1Q Trunking Analyzer

Parse VLAN allowed lists, calculate tag overhead, and plan QinQ MTU impact.

VLAN Allowed List Parser

VLAN List (e.g. 1-10,20,100-200,4094)

802.1Q Tag Overhead Calculator

Base MTU (bytes)

Tagging Mode

Link Speed (Gbps)

QinQ / 802.1ad Double-Tag Planning

Frame Type	Tag Bytes	EtherType	Fields Added
Untagged 802.3	0	—	—
802.1Q (dot1q)	+4	0x8100	TPID (2) + TCI: PCP(3) + DEI(1) + VID(12)
QinQ / 802.1ad	+8	0x88A8 outer	Outer tag (4) + inner 802.1Q tag (4)