R0106-HP MSR Router Series Layer 3 - IP Services Command Reference(V7)

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Usage guidelines
It is a good practice to specify the IPv6 address of the loopback interface as the source IPv6 address for
outgoing ping echo request and ICMPv6 error messages. This feature helps users to locate the sending
device easily.
Examples
# Specify IPv6 address 1::1 as the source address for outgoing ICMPv6 packets.
<Sysname> system-view
[Sysname] ipv6 icmpv6 source 1::1
ipv6 mtu
Use ipv6 mtu to set the MTU of IPv6 packets sent over an interface.
Use undo ipv6 mtu to restore the default MTU.
Syntax
ipv6 mtu mtu-size
undo ipv6 mtu
Default
No MTU is configured for an interface.
Views
Interface view
Predefined user roles
network-admin
Parameters
mtu-size: Specifies the size of the MTUs of an interface, in the range of 1280 to 10240 bytes.
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, configure an appropriate interface MTU for your network.
Examples
# Set the MTU of IPv6 packets over GigabitEthernet 2/1/1 to 1280 bytes.
<Sysname> system-view
[Sysname] interface gigabitethernet 2/1/1
[Sysname-GigabitEthernet2/1/1] ipv6 mtu 1280
ipv6 nd autoconfig managed-address-flag
Use ipv6 nd autoconfig managed-address-flag to set the managed address configuration (M) flag to 1
so that the host can obtain an IPv6 address through stateful autoconfiguration (for example, from a
DHCPv6 server).
Use undo ipv6 nd autoconfig managed-address-flag to restore the default.