Quality of Service (QoS): Managing Bandwidth More Effectively 
QoS Operating Notes and Restrictions 
QoS Operating Notes and Restrictions 
Table 8-15.  Details of Packet Criteria and Restrictions for QoS Support 
Packet 
Criteria or 
Restriction 
QoS Classifiers  DSCP 
Overwrite 
(Re-
Marking) 
UDP/TCP  Device 
Priority (IP 
Address) 
IP Type-of-
Service 
Layer 3 
Protocol 
VLAN  Source 
Port 
Incoming 
802.1p 
Restricted to 
IPv4 Packets 
Only 
Yes  Yes  Yes  No  No  No  No  Yes 
Allow Packets 
with IP Options
1 
3400cl and 
6400cl: No 
5300xl: Yes
3 
3400cl and 
6400cl: Yes 
5300xl: Yes
3 
3400cl and 
6400cl: Yes 
5300xl: Yes
3 
3400cl and 
6400cl: Yes 
5300xl: Yes
3 
3400cl and 
6400cl: Yes 
5300xl: Yes
3 
3400cl and 
6400cl: Yes 
5300xl: Yes
3 
3400cl and 
6400cl: Yes 
5300xl: Yes
3 
3400cl and 
6400cl: Yes 
5300xl: No 
Support IPv6 
Packets
2 
No  No  No  3400cl and 
6400cl: n/a 
5300xl: Yes 
Yes  Yes  Yes  No 
Support Layer-2 
SAP 
Encapsulation 
3400cl and 
6400cl: No 
5300xl: Yes 
3400cl and 
6400cl: No 
5300xl: Yes 
3400cl and 
6400cl: No 
5300xl: Yes 
3400cl and 
6400cl: No 
5300xl: Yes 
3400cl and 
6400cl: Yes 
5300xl: Yes 
3400cl and 
6400cl: Yes 
5300xl: Yes 
3400cl and 
6400cl: Yes 
5300xl: Yes 
3400cl and 
6400cl: No 
5300xl: Yes 
1
An “IP Option” is an optional, extra field in the header of an IP packet. If a 3400cl or 6400cl switch is configured with a 
UDP/TCP classifier and a packet with an IP option is received, the switch uses the next-highest classifier that is configured 
and applicable to actually match and classify the packet. 
2
All Switches: For explicit QoS support of IPv6 packets, force IPv6 traffic into its own set of VLANs and then configure 
VLAN-based classifiers for those VLANs. 
3
On IPv4 packets with IP options, the 5300xl switches support QoS for 802.1p priority policies, but does not do any DSCP 
re-marking for DSCP policies. 
■  All Switches: For explicit QoS support of IP subnets, HP recommends 
forcing IP subnets onto separate VLANs and then configuring VLAN-based 
classifiers for those VLANs. 
■  For Devices that Do Not Support 802.1Q VLAN-Tagged Ports: 
For communication between these devices and the switch, connect 
the device to a switch port configured as Untagged for the VLAN in 
which you want the device’s traffic to move. 
■  Port Tagging Rules: For a port on the switch to be a member of a 
VLAN, the port must be configured as either Tagged or Untagged for 
that VLAN. A port can be an untagged member of only one VLAN of 
a given protocol type. Otherwise, the switch cannot determine which 
VLAN should receive untagged traffic. For more on VLANs, refer to 
chapter 
2, “Static Virtual LANs (VLANs)”. 
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