Changing the Default Queuing and Marking of Host Outbound Traffic
You can modify the default forwarding class and DSCP bits used in the ToS field of host outbound traffic (packets generated by the Routing Engine). You can also modify the queue assignment of the forwarding class to which you assign host outbound traffic.
TCP-related packets, such as BGP or LDP, use queue 3 (network control) for retransmitted traffic. Changing the defaults for Routing Engine sourced traffic does not affect transit or incoming traffic. The changes apply to all packets relating to Layer 3 and Layer 2 protocols, but not MPLS EXP bits or IEEE 802.1p bits. This feature applies to all application-level traffic such as FTP or ping operations as well.
The forwarding class selected is global to the device. That is, the traffic is placed in the selected forwarding class on all egress interfaces. In the case of a restricted interface, the Routing Engine sourced traffic flows through the restricted queue.
The forwarding class selected must be properly configured on all interfaces.
To change the default forwarding class and DSCP bits for Routing Engine sourced traffic,
include the host-outbound-traffic statement at the [edit
class-of-service] hierarchy level:
[edit class-of-service] host-outbound-traffic { forwarding-class class-name; dscp-code-point value; }
The following example places all Routing Engine sourced traffic into the network control forwarding class (assigned to queue 3 by default) with a DSCP value of 101010:
[edit class-of-service]
host-outbound-traffic {
forwarding-class network-control;
dscp-code-point 101010;
}
You can also modify the queue assignment of the forwarding class. For example:
[edit class-of-service]
forwarding-classes {
class network-control queue-num 5;
}