Quality of Service (QoS): Managing Bandwidth More Effectively
IP Multicast (IGMP) Interaction with QoS
IP Multicast (IGMP) Interaction with QoSIGMP
The switch’s ability to prioritize IGMP traffic for either a normal or high priority outbound queue overrides any QoS criteria, and does not affect any 802.1p priority settings the switch may assign. For a given packet, if both IGMP high priority and QoS are configured, the QoS classification occurs and the switch marks the packet for downstream devices, but the packet is serviced by the
IGMP High | QoS Configuration | Switch Port Output | Outbound 802.1p Setting |
Priority | Affects Packet | Queue | (Requires Tagged VLAN) |
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Not Enabled | Yes | Determined by QoS | Determined by QoS |
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Enabled | See above para- | High | As determined by QoS if QoS is |
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Message | Meaning |
DSCP Policy < | You have attempted to map a QoS classifier to |
configured | a codepoint for which there is no configured |
| priority |
| command to configure a priority for the |
| codepoint, then map the classifier to the |
| codepoint. |
Cannot modify DSCP Policy < codepoint > - in use by other qos rules.
You have attempted to map a QoS classifier to a codepoint that is already in use by other QoS classifiers. Before remapping the codepoint to a new priority, you must reconfigure the other QoS classifiers so that they do not use this codepoint. You can have multiple QoS classifiers use this same codepoint as long as it is acceptable for all such classifiers to use the same priority.