(Optional) Configuring the DSCP of Protocol Packets
You can set the Differentiated Services Code Point (DSCP) values of management or control protocol packets sent by the local device, and enable protocol packets to enter the specified internal priority queue and obtain corresponding colors based on the DSCP values.
Context
Currently, when the NetEngine 8000 F performs internal scheduling on protocol packets, by default, the NetEngine 8000 F places protocol packets to the CS6 queue without the color, and the priority of the packets remains unchanged. If you use the CS6 queue for another purpose or not for service forwarding, services are affected. In addition, on the downstream device, scheduling requirements of specified protocol packets may fail to be met because these packets may enter the low-priority QoS queue. Therefore, to allow for flexible packet scheduling, allow these packets to enter other queues.
Procedure
- Run system-view
The system view is displayed.
- Run host-packet type { management-protocol | control-protocol } dscp dscp-value
The DSCP value of management or control protocol packets is set.
Generally, each protocol has a default DSCP value, and the DSCP values of some protocols can be configured using the host-packet type command or the corresponding commands for changing the DSCP values of the protocols. In this case, the rules for the DSCP values to take effect as follows:
- If a protocol has its own command for changing the DSCP value, the DSCP value configured using its own command takes effect regardless of whether the DSCP value is controlled by the host-packet type command.
- If a protocol does not have its own command for changing the DSCP value and the DSCP value is controlled by the host-packet type command, the DSCP value configured using the command takes effect.
- If a protocol does not have its own command for changing the DSCP value and the DSCP value is not controlled by the host-packet type command, the default DSCP value takes effect.
For details about the DSCP value and meaning of each PHB, see DSCP and PHB.
Table 1 and Table 2 describe how to change the ToS/DSCP value of the IPv4 protocol and the traffic class/DSCP value of the IPv6 protocol, respectively.
Table 1 ToS/DSCP value of IPv4 and its modification method Protocol
Default ToS/DSCP Value
Controlled by the host-packet type Command
Modification Command for Each Protocol
ICMP_ECHO
0
No
ping -dscp dscp-value
ICMP_ECHO_REPLY
0
No
N/A
ICMP Error
6
No
N/A
DNS
0
No
N/A
FTP
6
Yes (host-packet type management-protocol)
N/A
TFTP
6
Yes (host-packet type management-protocol)
N/A
SNMP
6
Yes (host-packet type management-protocol)
snmp-agent packet-priority snmp priority-level
SSH
6
Yes (host-packet type management-protocol)
ssh server dscp value
Telnet
6
Yes (host-packet type management-protocol)
telnet server dscp value
Syslog (UDP)
0
Yes (host-packet type management-protocol)
info-center syslog packet-priority priority-level
The info-center syslog packet-priority priority-level command takes precedence over the host-packet type management-protocol command.
Syslog (TCP)
0
No
info-center syslog packet-priority priority-level
HWTACACS
6
Yes (host-packet type management-protocol)
N/A
RADIUS
6
No
N/A
NTP
6
Yes (host-packet type control-protocol)
N/A
BFD
7
No
tos-exp tos-value (BFD session view)
tos-exp tos-value { dynamic | static } (BFD view)
IGMP
6
No
N/A
PIM
6
No
N/A
CUSP
6
Yes (host-packet type control-protocol)
N/A
BGP
6
Yes (host-packet type control-protocol)
N/A
LDP
6
Yes (host-packet type control-protocol)
N/A
OSPF
6
Yes (host-packet type control-protocol)
N/A
DHCP Server/DHCP Relay
6
No
dhcp dscp-outbound value
DHCP Snooping
0
No
N/A
GRE
If the inner IP ToS is valid, the ToS/DSCP value of the inner IP packet is inherited. Otherwise, it is set to 6.
No
N/A
IKE
6
No
N/A
VXLAN
If the inner IP ToS is valid, the ToS/DSCP value of the inner IP packet is inherited. Otherwise, it is set to 6.
No
N/A
RSVP-TE
6
No
N/A
MSDP
6
No
N/A
Table 2 Traffic class/DSCP value of IPv6 and its modification method Protocol
Default Traffic Class/DSCP Value
Controlled by the host-packet type Command
Modification Command for Each Protocol
ICMP6_ECHO
0
No
ping ipv6 -tc traffic-class-value
ICMP6_ECHO_REPLY
Copied from the TC/DSCP value of an ICMP6_ECHO message
No
N/A
ICMP6 Error
Copied from the TC/DSCP value of an ICMP6_ECHO message
No
N/A
ND (NS/NA/RS/RA)
6
No
N/A
TNL6 (IPv6 over IPv4)
0
No
N/A
TNL6 (IPv4 over IPv6)
0
No
tunnel ipv4-ipv6 traffic-class class-value
DNSv6
0
No
N/A
FTPv6
6
No
N/A
TFTPv6
6
No
N/A
SNMPv6
6
No
snmp-agent packet-priority snmp priority-level
SSHv6
6
No
N/A
Telnetv6
6
No
N/A
Syslog (UDP)
0
No
info-center syslog packet-priority priority-level
Syslog (TCP)
0
No
info-center syslog packet-priority priority-level
HWTACACS
6
No
N/A
RADIUS
6
No
N/A
NTPv6
6
No
N/A
BFDv6
7
No
tos-exp tos-value (BFD session view)
tos-exp tos-value { dynamic | static } (BFD view)
MLD
6
No
N/A
PIMv6
6
No
N/A
BGP4+
6
No
N/A
OSPFv3
6
No
N/A
DHCPv6
6
No
N/A
GRE
If the inner IP TC is valid, the TC/DSCP value of the inner IP packet is inherited. Otherwise, it is set to 6.
No
N/A
VXLAN
If the inner IP TC is valid, the TC/DSCP value of the inner IP packet is inherited. Otherwise, it is set to 6.
No
N/A
- Run host-packet dscp dscp-value map local-service cos-value [ color color ]
Mappings between DSCP values of protocol packets and internal priorities and between DSCP values and colors are configured.
The DSCP value in the host-packet type command only indicates the priority of protocol packets. 802.1p priorities of Layer 2 protocol packets are mapped from the DSCP value based on the DS domain configured on the outbound interface. EXP priorities of MPLS packets are the leftmost 3 bits of DSCP value. If this command is not used, sent protocol packets carry the preconfigured priority.
- Run commit
The configuration is committed.