MTU Cheat Sheet

• text version
• raw (Directly-connected Ethernet)
• NTT/PPPoE_v4 (NTT E/W IPv4 via PPPoE, including B-Flets and Hikari-Next(East only))
• NTT/PPPoE_v4+OCN_v6 (OCNv6 over NTTe+w/PPPoE/IPv4)
• NTT/pre_isp_v4+OCN_v6 (OCNv6 over NTTw/IPv4)
• NTTe/dnet_v6 (NTT E, Flets.NET IPv6)
• NTTw/pre_isp_v4 (NTT W, IPv4)
• NTTw/pre_square_v6 (NTT W, IPv6 Hikari-Premium)
• OCN_v6 (NTT-Com, OCN IPv6 via L2TPoUDP)

raw

	Minimum headers for transportation of original L2 payload
	GREv4
	GREv6
	GIFv4
	GIFv6
	EthIPv4
	EthIPv6
	L2TPv2-UDPv4
	L2TPv2-UDPv6
	L2TPv3-UDPv4
	L2TPv3-UDPv6
	VTUNv4
	VTUNv6

NTT/PPPoE_v4

	Minimum headers for transportation of original L2 payload
	GREv4
	GIFv4
	EthIPv4
	L2TPv2-UDPv4
	L2TPv3-UDPv4
	VTUNv4

NTT/PPPoE_v4+OCN_v6

	Minimum headers for transportation of original L2 payload
	GREv6
	GIFv6
	EthIPv6
	L2TPv2-UDPv6
	L2TPv3-UDPv6
	VTUNv6

NTT/pre_isp_v4+OCN_v6

	Minimum headers for transportation of original L2 payload
	GREv6
	GIFv6
	EthIPv6
	L2TPv2-UDPv6
	L2TPv3-UDPv6
	VTUNv6

NTTe/dnet_v6 = raw

NTTw/pre_isp_v4

	Minimum headers for transportation of original L2 payload
	GREv4
	GIFv4
	EthIPv4
	L2TPv2-UDPv4
	L2TPv3-UDPv4
	VTUNv4

NTTw/pre_square_v6 = raw

OCN_v6

	Minimum headers for transportation of original L2 payload
	GREv6
	GIFv6
	EthIPv6
	L2TPv2-UDPv6
	L2TPv3-UDPv6
	VTUNv6