HP 6125G HP 6125G & 6125G/XG Blade Switches Layer 2 - LAN Switching Co - Page 144

Configuration restrictions and guidelines, Configuration procedure, Configuring a port to operate

Page 144 highlights

values, for voice traffic. Voice traffic carries its own QoS priority settings. You can configure the device either to modify or not to modify the QoS priority settings carried by incoming voice traffic. Configuration restrictions and guidelines Configure the QoS priority settings for voice traffic on an interface before you enable voice VLAN on the interface. If the configuration order is reversed, your priority trust setting will fail. Configuration procedure To configure QoS priority settings for voice traffic: Step Command 1. Enter system view. system-view 2. Enter Layer 2 Ethernet interface view. interface interface-type interface-number 3. Configure the interface to trust the QoS priority settings in incoming voice traffic, but not to modify the CoS and DSCP voice vlan qos trust values marked for incoming traffic of the voice VLAN. 4. Configure the interface to modify the CoS and DSCP values marked for incoming traffic of the voice VLAN into voice vlan qos cos-value dscp-value specified values. Remarks N/A N/A Use either command. By default, an interface modifies the CoS value and the DSCP value marked for voice VLAN traffic into 6 and 46, respectively. The voice vlan qos command and the voice vlan qos trust command can overwrite each other, whichever is configured last. Configuring a port to operate in automatic voice VLAN assignment mode Configuration restrictions and guidelines • A protocol-based VLAN on a hybrid port can process only untagged inbound packets, whereas the voice VLAN in automatic mode on a hybrid port can process only tagged voice traffic. Do not configure a VLAN as both a protocol-based VLAN and a voice VLAN. For more information, see "Configuring VLANs." • Do not configure automatic voice VLAN assignment together with MSTP, because the former is mainly configured on the access side. With MSTP enabled, if a port is blocked in the MST instance (MSTI) of the target voice VLAN, the port drops the received packets, instead of delivering them to the CPU. As a result, the receiving port will not be dynamically assigned to the corresponding VLAN. • Do not configure automatic voice VLAN assignment together with PVST, because the former is mainly configured on the access side. With PVST enabled, if the target voice VLAN is not permitted on a port, the port is placed in the blocked state and drops the received packets, instead of delivering them to the CPU. As a result, the receiving port will not be dynamically assigned to the corresponding VLAN. 135

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135
values, for voice traffic. Voice traffic carries its own QoS priority settings. You can configure the device
either to modify or not to modify the QoS priority settings carried by incoming voice traffic.
Configuration restrictions and guidelines
Configure the QoS priority settings for voice traffic on an interface before you enable voice VLAN on the
interface. If the configuration order is reversed, your priority trust setting will fail.
Configuration procedure
To configure QoS priority settings for voice traffic:
Step
Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter Layer 2 Ethernet
interface view.
interface
interface-type
interface-number
N/A
3.
Configure the interface to trust
the QoS priority settings in
incoming voice traffic, but not
to modify the CoS and DSCP
values marked for incoming
traffic of the voice VLAN.
voice vlan qos
trust
Use either command.
By default, an interface modifies the CoS
value and the DSCP value marked for voice
VLAN traffic into 6 and 46, respectively.
The
voice vlan qos
command and the
voice
vlan qos trust
command can overwrite each
other, whichever is configured last.
4.
Configure the interface to
modify the CoS and DSCP
values marked for incoming
traffic of the voice VLAN into
specified values.
voice vlan qos
cos-value
dscp-value
Configuring a port to operate in automatic voice
VLAN assignment mode
Configuration restrictions and guidelines
A protocol-based VLAN on a hybrid port can process only untagged inbound packets, whereas the
voice VLAN in automatic mode on a hybrid port can process only tagged voice traffic. Do not
configure a VLAN as both a protocol-based VLAN and a voice VLAN. For more information, see
"
Configuring VLANs.
"
Do not configure automatic voice VLAN assignment together with MSTP, because the former is
mainly configured on the access side. With MSTP enabled, if a port is blocked in the MST instance
(MSTI) of the target voice VLAN, the port drops the received packets, instead of delivering them to
the CPU. As a result, the receiving port will not be dynamically assigned to the corresponding
VLAN.
Do not configure automatic voice VLAN assignment together with PVST, because the former is
mainly configured on the access side. With PVST enabled, if the target voice VLAN is not permitted
on a port, the port is placed in the blocked state and drops the received packets, instead of
delivering them to the CPU. As a result, the receiving port will not be dynamically assigned to the
corresponding VLAN.