Netis ST3326(ST-3302) [87/118] Configuring priority trust mode

3) Local precedence

Local precedence is a locally significant precedence that the device assigns to a packet. A local

precedence value corresponds to one of the eight hardware output queues. Packets with the

highest local precedence are processed preferentially. As local precedence is used only for

internal queuing, a packet does not carry it after leaving the queue.

Configuring Priority trust mode

After a packet enters a switch, the switch sets the 802.1p priority and local precedence for the

packet according to its own capability and the corresponding rules.

1) For a packet carrying no 802.1q tag

When a packet carrying no 802.1q tag reaches a port, the switch uses the port priority as the

802.1p precedence value of the received packet, searches for the local precedence

corresponding to the port priority of the receiving port in the 802.1p-to-local precedence

mapping table, and assigns the local precedence to the packet.

2) For an 802.1q tagged packet

For incoming 802.1q tagged packets, you can configure the switch to trust packet priority or to

trust port priority. By default, the switches trust port priority.

 Trusting port priority

In this mode, the switch replaces the 802.1p priority of the received packet with the port priority,

searches for the local precedence corresponding to the port priority of the receiving port in the

802.1p-to-local precedence mapping table, and assigns the local precedence to the packet.

 Trusting packet priority

After configuring to trust packet priority, you can specify the trusted priority type, which can be

802.1p priority, DSCP precedence, or IP precedence. With trusting packet priority enabled, the

switch trusts the 802.1p priority of received packets.

The switches provide 802.1p-to-local-precedence, DSCP-to-local-precedence, and

IP-to-local-precedence mapping tables for priority mapping.

Priority Marking

The priority marking function is to reassign priority for the traffic matching an ACL referenced for

traffic classification.

 If 802.1p priority marking is configured, the traffic will be mapped to the local precedence

corresponding to the re-marked 802.1p priority and assigned to the output queue

corresponding to the local precedence.

 If local precedence marking is configured, the traffic will be assigned to the output queue