Managing Switches

Configuring Switch Features

3

Protocol Priority

The switch can prioritize outbound packets for one or more of these

 

 

network protocols: IP, IPX, ARP, DECNet, AppleTalk, SNA, and NetBEUI.

 

 

Default state: No override for any protocol.

 

 

If a packet does not meet the criteria for Protocol priority, then

 

 

precedence defaults to VLAN criteria, below.

 

 

 

4

VLAN Priority

Enables packet priority based on the name of the VLAN in which the

 

 

packet exists. For example, if the default VLAN (DEFAULT_VLAN) and

 

 

the “Blue” VLAN are both assigned to a port, and Blue VLAN traffic is

 

 

more important, you can configure CoS to give Blue VLAN traffic a

 

 

higher priority than DEFAULT_VLAN traffic. (Priority is applied on the

 

 

outbound port.) Default state: No override.

 

 

If a packet does not meet the criteria for VLAN priority, then precedence

 

 

defaults to Incoming 802.1p criteria, below.

 

 

 

5

Incoming 802.1p Priority

When a packet enters the switch on a tagged VLAN, if CoS is not

 

 

configured to apply to the packet’s priority setting, the switch uses the

 

 

packet’s existing 802.1p priority (assigned by an upstream device or

 

 

application) to determine which outbound port queue to use. If the

 

 

packet leaves the switch on a tagged VLAN, then there is no change to

 

 

its 802.1p priority setting. If the packet leaves the switch on an undated

 

 

VLAN, the 802.1p priority is dropped.

 

 

Entering (Inbound) 802.1pPriority

 

 

0-3

 

 

4-7

 

 

Outbound Port Queue

 

 

Normal

 

 

High

 

 

Exiting (Outbound 802.1p Priority)

 

 

0-3

 

 

4-7

 

 

If a packet does not meet the criteria for Incoming 802.1p priority, then

 

 

the packet is sent to the “normal” outbound queue of the appropriate

 

 

port. If the packet did not enter the switch on a tagged VLAN, but exits

 

 

from the switch on a tagged VLAN, then a tagged VLAN field, including

 

 

an 802.1p priority of 0 (normal), is added to the packet.

 

 

 

Assigning a Monitoring Port

The Monitor Port tab (only found on switches) lets you select a “Monitoring Port” that you can use with a network analyzer to monitor other ports on the switch. For the HP J3298A and HP J3299A you can only choose the Monitoring port and the port to be monitored. For other switches you can choose to have all the ports for one VLAN monitored, or you can select individual ports to be monitored. See the online help for information on specific switches.

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