12-11
Cisco 10000 Series Router Quality of Service Configuration Guide
OL-7433-09
Chapter 12 Sharing Bandwidth Fairly During Congestion
Configuring Fair Bandwidth Sharing During Congestion
Configuring a Class Policy and Dropping Packets Using Tail Drop
To configure a class policy and drop packets using tail drop, enter the following commands beginning in
global configuration mode:
Note
Repeat Steps 2 through 4 to configure additional classes in the policy map.
Command
Purpose
Step 1
Router(config)#
policy-map
policy-map-name
Creates or modifies a policy map. Enters policy-map
configuration mode.
policy-map-name
is the name of the policy map.
Step 2
Router(config-pmap)#
class
class-map-name
Assigns a traffic class to a policy map. Enters policy-map class
configuration mode.
class-map-name
is the name of a previously configured class
map.
Step 3
Router(config-pmap-c)#
bandwidth
{
bandwidth-kbps
|
percent
percentage
|
remaining percent
percentage
}
Specifies the amount of bandwidth (in kbps or as a percentage of
available bandwidth) to be assigned to the class. The amount of
bandwidth configured should be large enough to also
accommodate Layer 2 overhead.
bandwidth-kbps
specifies or modifies the minimum bandwidth
allocated for a class belonging to a policy map. Valid values are
from 8 to 2,488,320, which represents from 1 to 99 percent of the
link bandwidth.
Note
The range of valid values for
bandwidth-kbps
might be
smaller than the values indicated above. Use the question
mark (?) in context-sensitive help to display the range of
valid values.
percent
percentage
specifies or modifies the minimum
percentage of the link bandwidth allocated for a class belonging
to a policy map. Valid values are from 1 to 99.
remaining percent
percentage
specifies or modifies the
minimum percentage of unused link bandwidth allocated for a
class belonging to a policy map. Valid values are from 1 to 99.
Step 4
Router(config-pmap-c)#
queue-limit
number-of-packets
Specifies the maximum number of packets that the queue can
accumulate for this class.
number-of-packets
is a number from 1 to 64. The default number
of queue entries is based on the bandwidth rate.
Note
When you specify the
queue-limit
command, the router
uses tail drop to drop packets.