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302 Chapter 10: Managing Network Performance with Queuing and Compression

With the priority queuing nuances in mind, it is apparent that some planning needs to go into
the creation of the list. Packets that do not match other assignment rules are assigned to the
default queue. The tasks involved in the configuration are as follows:

Define specific access lists (if they are to be used).

Create the priority list.

Apply the priority list to the interface.

Verify the queuing process.

Defining Specific Access Lists

If it is necessary to queue traffic based on a specific network address, protocol, or application,
access lists can be put in place to sort the traffic. Standard or extended access lists can be defined
to specify the traffic type or types that should be placed into a specific queue.

Access list configuration is not discussed in this book. For additional information on access
lists, check out www.cisco.com and perform a search on "access-list."

Creating the Priority List

The following command syntax shows the command parameters for priority queue
configuration for a specific protocol or traffic type:

RouterA(config)#priority-list list-number protocol protocol-name
{high | medium | normal | low} queue-keyword keyword-value

The list-number argument can be an arbitrarily selected number from 116; however, all lines
for a particular priority list must have the same list-number to function properly. queue-keyword
and keyword-value are used to associate access lists with the priority list. Example 10-1 shows
a configuration that utilizes the priority-list command.

The access-list line in Example 10-1 specifies Telnet as the specific traffic type for which to
search. The priority-list specifies that any traffic matching access list 101 should be placed into
the high-priority queue.

Example 10-1

priority-list Configuration with Access Lists

RouterA(config)#access-list 101 permit tcp any any eq telnet
RouterA(config)#priority-list 1 protocol ip high list 101
RouterA(config)#priority-list 1 protocol ip medium
RouterA(config)#priority-list 1 protocol ipx medium
RouterA(config)#priority-list 1 protocol Appletalk normal
RouterA(config)#interface serial 0
RouterA(config-if)#priority-group 1