The simplest way to classify a packet is to use behavior aggregate classification. The DSCP, DSCP IPv6, or IP precedence bits of the IP header convey the behavior aggregate class information. The information might also be found in the MPLS EXP bits or IEEE 802.1p CoS bits.
You can configure the following classifier types:
If you apply an IEEE 802.1 classifier to a logical interface, this classifier takes precedence and is not compatible with any other classifier type. On MX-series routers using IEEE 802.1ad frame formats, you can apply classification on the basis of the IEEE 802.1p bits (three bits in either the inner VLAN tag or the outer VLAN tag) and the drop eligible indicator (DEI) bit. On routers with IQ2 PICs using IEEE 802.1ad frame format, you can apply classification based on the IEEE 802.1p bits and the DEI bit. Classifiers for IP (DSCP or IP precedence) and MPLS (EXP) can coexist on a logical interface if the hardware platform requirements are met. (See Table 25.)