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Hierarchy Level


On IQ, MPC, and DPC interfaces on M120, T320, T640, T1600, TX Matrix, and TX Matrix Plus routers, or on MIC or MPC interfaces on MX Series routers, set the number of egress queues per port to four or eight.


If you include the max-queues-per-interface 8 statement, the configuration at the [edit class-of-service] hierarchy level must also support eight queues per interface.


When you include the max-queues-per-interface statement and commit the configuration, all physical interfaces on the line card are deleted and readded. Also, the FPC/MPC restarts automatically. If the FPC/MPC is a fixed-configuration line card, that does not contain a MIC or PIC, you should restart the FPC/MPC to apply the configuration. You should change modes between four queues and eight queues only when there is no active traffic going to the FPC/MPC or to the PIC/MIC.

By default, IQ PICs on T Series and M320 routers are restricted to a maximum of four egress queues per interface. If you include the max-queues-per-interface 4 statement, you can configure all four ports and configure up to four queues per port.

For Quad T3 and Quad E3 PICs and for 4-port OC3c/STM1 Type I and Type II PICs on M320 and T Series routers, when you include the max-queues-per-interface 8 statement, you can configure up to eight queues on ports 0 and 2. After you commit the configuration, the PIC goes offline and comes back online with only ports 0 and 2 operational. No interfaces can be configured on ports 1 and 3.


Starting from Junos OS Release 14.1R8, 14.2R6, 15.1F6, 15.1R3, 15.1R4, and 16.1R1, the restricted queue PICs without the max-queues-per-interface configuration boot up with a maximum of eight queues per port and two operational ports (port 0 and 2). PICs with restricted queues include Quad T3 PIC, Quad E3 PIC, 4-port SONET/SDH OC3c/STM1 PIC, and 4-Port OC3 and 1-port OC12 PICs with SFP.

On certain older MPCS (MPC1 Q, MPC1E Q, MPC2 Q, MPC2E Q), you can include the max-queues-per-interface statement to set the number of queues per logical interface to four or eight. Setting max-queues-per-interface 4 sets the MPC to have four queues per logical interface and provides twice as many logical interfaces on the MPC as setting max-queues-per-interface 8.


For consistency, max-queues-per-interface should not be set on MPCs starting from Junos OS 14.1X51.

Required Privilege Level

interface—To view this statement in the configuration.

interface-control—To add this statement to the configuration.

Release Information

Statement introduced before Junos OS Release 7.4.

Support for TX Matrix and TX Matrix Plus added in Junos OS Release 9.6.