CoS-Based Interface Counters for IPv4 or IPv6 Aggregate on Layer 2
Beginning with Junos OS Release 14.1, Layer 2 CoS-based traffic metering is available for MX series routers with MPCs and MX80 routers. It can be used in greenfield deployments or as a replacement for term-matching counters configured via firewall filters. (Term-matching counters configured via firewall filters can have several drawbacks, including a one-filter-per-family limit, the inclusion of overhead bytes, and less operational efficiency than CoS-based counters). With CoS-based counters, a single aggregate counter per forwarding class can be used for inet and inet6 flows. Both bytes and packet total are counted. Note that flow rates are not measured, and forwarding-class accounting for host-bound traffic is not supported.
You can configure the counters with any or all of the following parameters:
Logical | physical interfaces
IPv4 | IPv6 traffic
Unicast | multicast traffic
Ingress | egress flows
CoS-based interface counters are highly accurate and can be
configured to exclude overhead bytes (such as protocol encapsulations)
so end-customer packets can be differentiated from other traffic.
At ingress only packets forwarded to the fabric are counted, and at
egress only packets forwarded to the WAN are counted. In other words, forwarding-class accounting applies to transit traffic only,
not host-generated or host-bound traffic. Non-relevant network protocols
such as ARP, BFD, and EOAM, as well as dropped packets, are not counted.
To support native interface counters, a new CLI option, enhanced, is introduced under forwarding-class accounting at both the physical and logical interface levels:
interfaces {
interface-name{
forwarding-class-accounting {
enhanced {
overhead-bytes overhead-value(;
traffic-type (ucast | mcast);
family (ipv4 | ipv6 | both );
direction (ingress | egress | both);
}
}
}
}
To view additional counter details, run the following show commands:
show interfaces forwarding-class-counters interface-nameshow class-of-service interface interface-name comprehensiveshow class-of-service interface interface-name detail
The comprehensive option shows both forwarding-class
accounting parameters and the forwarding-class counter, whereas detail shows only the forwarding-class accounting parameters.
It does not display counters for each forwarding class.