R2511-HP MSR Router Series ACL and QoS Configuration Guide(V5)

Configuring packet information pre-extraction

If a tunnel interface has processed an incoming IP packet, for example, if the tunnel interface has used

GRE to encapsulate a packet, the GRE-encapsulated packet enters the QoS module for processing. As a

result, the QoS module cannot get the IP information of the original packets.

To process the original IP packets with QoS on the physical interface for a logical interface, configure

packet information pre-extraction on the logical interface.

Configuration procedure

To configure packet information pre-extraction:

Ste

Command Remarks

1. Enter system view.

system-view N/A

2. Enter tunnel interface

view.

interface tunnel interface-number N/A

3. Enable packet

information

pre-extraction.

qos pre-classify

By default, packet

information pre-extraction

is disabled on a tunnel

interface.

Configuration example

Network requirements

Enable packet information pre-extraction on a tunnel interface.

Configuration procedure

# Enable packet information pre-extraction on tunnel interface Tunnel 0.

<Sysname> system-view

[Sysname] interface tunnel 0

[Sysname-Tunnel0] qos pre-classify

Configuring local fragment pre-drop

If the packet size is bigger than the MTU of the egress interface, the packet is fragmented into local

fragments. If the first fragment is dropped, the subsequent fragments become invalid fragments, and it is

insignificant to process and transmit these invalid fragments.

With local fragment pre-drop, if the first fragment of a packet is dropped by the QoS module, the

subsequent fragments will be dropped directly without undergoing QoS processing. The local fragment

pre-drop function improves the local fragment processing and transmitting efficiency, and reduces

subsequent invalid fragments' occupation of system resources and network bandwidth.

Local fragment pre-drop is mutually exclusive with matching fragments by fragment attributes or size.

Local fragment pre-drop applies to IPv4 and IPv6 local fragments.