Class of Service Configuration3-1373Web – Click Priority, ACL CoS Priority. Enable mapping for any port, select an ACLfrom the scroll-down list, then click Apply.Figure 3-81. ACL CoS PriorityCLI – This example assigns a CoS value of zero to packets matching rules withinthe specified ACL on port 24.Changing Priorities Based on ACL RulesYou can change traffic priorities for frames matching the defined ACL rule. (Thisfeature is commonly referred to as ACL packet marking.) This switch can change theIEEE 802.1p priority, IP Precedence, or DSCP Priority of IP frames; or change theIEEE 802.1p priority of Layer 2 frames.Command Usage• You must configure an ACL mask before you can change priorities based on a rule.• Traffic priorities may be included in the IEEE 802.1p priority tag. This tag is alsoincorporated as part of the overall IEEE 802.1Q VLAN tag. The 802.1p priority maybe set for either Layer 2 or IP frames.• The IP frame header also includes priority bits in the Type of Service (ToS) octet.The Type of Service octet may contain three bits for IP Precedence or six bits forDifferentiated Services Code Point (DSCP) service. Note that the IP frame headercan include either the IP Precedence or DSCP priority type.• The precedence for priority mapping by this switch is IP Precedence or DSCPPriority, and then 802.1p priority.Console(config)#interface ethernet 1/24 4-125Console(config-if)#map access-list ip bill cos 0 4-98Console(config-if)#
