Advanced Traffic Management Guide K/KA/KB.15.15

4. Configure the switch to assign the DSCP policy to packets with the specified IP address or
subnet mask.
Syntax:
qos device-priority [ ipv4-address | [ipv4 ipv4-address/mask-length]]
dscp codepoint
qos device-priority [ ipv6-address | ipv6 ipv6-address/mask-length ]
dscp codepoint
Assigns a DSCP policy in packets with the specified IP address or subnet mask in
the source or destination field in a packet header, where:
• ipv4-address or ipv6-address is an IPv4 or IPv6 address used to match
the source or destination address in packet headers.
NOTE: An IPv6 local-link address (such as fe80::110:252%vlan20) that
is automatically generated on a VLAN interface is not supported as an
ipv6-address value.
• [ipv4] ipv4-address/mask-length is the subnet identified by the IPv4
mask for the specified address that is used to match the IPv4 in the source or
destination field of packet headers.
• ipv6 ipv6-address/prefix-length is the subnet identified by the IPv6
prefix-length for the specified address that is used to match the IPv6 address
in the source or destination field of packet headers.
Enter the IPv4 mask or IPv6 prefix length with an address in CIDR format by
using the number of significant bits (for example,
2001:db8:2:1:262:a03:e102:127/64 or 10.28.31.1/24).
• dscp codepoint overwrites the DSCP codepoint in the IPv4 ToS byte or
IPv6 Traffic Class byte of matching packets with the specified value.
Valid values for the DSCP codepoint are as follows:
• A binary value for the six-bit codepoint from 000000 to 111111.
• A decimal value from 0 (low priority) to 63 (high priority) that corresponds
to a binary DSCP bit set
• An ASCII standard name for a binary DSCP bit set Enter ? to display the
list of valid codepoint entries.
The DSCP value you enter must be currently associated with an 802.1p
priority in the DSCP Policy table (see Table 23 (page 255)). The 802.1p
priority and determines the packet's queue in the outbound port to which
it is sent. If the packet leaves the switch on a tagged port, it carries the
802.1p priority with it to the next downstream device. The default DSCP
codepoint is No-override. The DSCP codepoint is not overwritten in
matching packets.
The no form of the command deletes the specified IP address or subnet
mask as a QoS classifier. If you configured a subnet mask as match
criteria, you must enter the entire IP address and mask-length in the no
command.
Syntax:
show qos device-priority
Displays a listing of all IP addresses and subnet masks used as QoS classifiers
currently in the running-config file.
Creating a policy based on IP address 201