Default Junos OS CoS Settings
If you do not configure any CoS settings on your router, the software performs some CoS functions to ensure that user traffic and protocol packets are forwarded with minimum delay when the network is experiencing congestion. Some default mappings are automatically applied to each logical interface that you configure. Other default mappings, such as explicit default classifiers and rewrite rules, are in operation only if you explicitly associate them with an interface.
You can display default CoS settings by issuing the show
class-of-service operational mode command. This section includes sample output displaying the default CoS
settings. The sample output is truncated for brevity.
show class-of-service
user@host> show class-of-service
Some platforms require an argument after the show
class-of-service command. The argument is to select a portion
of the following output to display.
Default Forwarding Classes
Forwarding class Queue best-effort 0 expedited-forwarding 1 assured-forwarding 2 network-control 3
Default Code-Point Aliases
Code point type: dscp Alias Bit pattern af11 001010 af12 001100 ... Code point type: dscp-ipv6 ... Code point type: exp ... Code point type: ieee-802.1 ... Code point type: inet-precedence ... Code point type: ieee-802.1ad ...
Default Classifiers
Classifier: dscp-default, Code point type: dscp, Index: 7 ... Classifier: dscp-ipv6-default, Code point type: dscp-ipv6, Index: 8 ... Classifier: exp-default, Code point type: exp, Index: 9 ... Classifier: ieee8021p-default, Code point type: ieee-802.1, Index: 10 ... Classifier: ipprec-default, Code point type: inet-precedence, Index: 11 ... Classifier: ipprec-compatibility, Code point type: inet-precedence, Index: 12 ... Classifier: ieee8021ad-default, Code point type: ieee-802.1ad, Index: 41 ...
Default Frame Relay Loss Priority Map
Loss-priority-map: frame-relay-de-default, Code point type: frame-relay-de, Index: 13 Code point Loss priority 0 low 1 high
Default Rewrite Rules
Rewrite rule: dscp-default, Code point type: dscp, Index: 24 Forwarding class Loss priority Code point best-effort low 000000 best-effort high 000000 ... Rewrite rule: dscp-ipv6-default, Code point type: dscp-ipv6, Index: 25 ... Rewrite rule: exp-default, Code point type: exp, Index: 26 ... Rewrite rule: ieee8021p-default, Code point type: ieee-802.1, Index: 27 ... Rewrite rule: ipprec-default, Code point type: inet-precedence, Index: 28 ... Rewrite rule: ieee8021ad-default, Code point type: ieee-802.1ad, Index: 42 ...
Default Drop Profile
Drop profile: <default-drop-profile>, Type: discrete, Index: 1
Fill level Drop probability
100 100
Default Schedulers
Scheduler map: <default>, Index: 2
Scheduler: <default-be>, Forwarding class: best-effort, Index: 17
Transmit rate: 95 percent, Rate Limit: none, Buffer size: 95 percent, Priority: low
Drop profiles:
Loss priority Protocol Index Name
Low Any 1 <default-drop-profile>
High Any 1 <default-drop-profile>
...