ipv6 mtu

Use ipv6 mtu to configure the MTU of IPv6 packets sent over an interface.

Use undo ipv6 mtu to restore the default MTU.

Syntax

ipv6 mtu size

undo ipv6 mtu

Default

No MTU is configured for an interface.

Views

Interface view

Predefined user roles

network-admin

mdc-admin

Parameters

size: Specifies the size of the MTUs of an interface in bytes. The value ranges for VLAN interfaces, Layer 3 Ethernet interfaces, and Layer 3 aggregate interfaces are 1280 to 9198, 1280 to 1560, and 1280 to 1500, respectively.

Usage guidelines

IPv6 routers do not support packet fragmentation. After an IPv6 router receives an IPv6 packet, if the packet size is greater than the MTU of the forwarding interface, the router discards the packet. Meanwhile, the router sends the MTU to the source host through an ICMPv6 packet — Packet Too Big message. The source host fragments the packet according to the MTU and resends it. To reduce the extra flow overhead resulting from packet drops, set an appropriate interface MTU for your network.

Examples

# Set the MTU of IPv6 packets sent over VLAN-interface 100 to 1280 bytes.

<Sysname> system-view
[Sysname] interface vlan-interface 100
[Sysname-Vlan-interface100] ipv6 mtu 1280