R2511-HP MSR Router Series Layer 3 - IP Services Configuration Guide(V5)

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• If super VLAN is used, the two hosts must belong to different sub VLANs.
• If isolate-user-VLAN is used, the two hosts must belong to different secondary VLANs.
Configuration procedure
You can enable local ND proxy in VLAN interface view, Layer 3 Ethernet interface view, or Layer 3
Ethernet subinterface view.
To enable local ND proxy:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter interface view.
interface interface-type
interface-number
N/A
3. Enable local ND proxy.
local-proxy-nd enable Disabled by default.
Configuring path MTU discovery
This section describes how to configure path MTU discovery.
Configuring the interface MTU
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 packets being discarded, a proper interface MTU should be configured
according to the actual networking environment.
To configure the interface MTU:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter interface view.
interface interface-type
interface-number
N/A
3. Configure the interface MTU.
ipv6 mtu mtu-size
Optional.
The default value is 1500.
Configuring a static path MTU for a specified IPv6 address
You can configure a static path MTU for a specified destination IPv6 address. When a source host sends
a packet through an interface, it compares the interface MTU with the static path MTU of the specified
destination IPv6 address. If the packet size is larger than the smaller one of the two values, the host
fragments the packet according to the smaller value.
To configure a static path MTU for a specified IPv6 address: