Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?


New and Changed Features


This section describes the new features and enhancements in this release.

  • CentOS support—vMX can be installed on a host running KVM on CentOS 7.2 operating system. You must prepare the host before installing vMX.

  • Class of Service support for drop profiles—You can manage congestion using drop profiles and packet loss priority. Packet loss priority (PLP) values are low, medium-low, medium-high, and high. Each packet loss priority value is mapped to a color that determines the behavior applied to an oversubscribed queue; low PLP maps to green, medium-low PLP and medium-high PLP map to yellow, and high PLP maps to red. Drop profiles are used to set the thresholds within a queue for a given loss priority.

  • Class of Service support for L2TP LNS—Hierarchical scheduling and per-session shaping can be applied to L2TP network server (LNS) inline service interfaces using a static or dynamic CoS configuration. You enable the inline service interface (si) for vMX by configuring the inline-services bandwidth (1g | 10g) option at the [edit chassis fpc 0 pic 0] hierarchy level. You must also create the loopback device for each si interface by configuring the loopback-device-count device-count option at the [edit chassis fpc 0] hierarchy level where device-count is the number of si interfaces in the range of 1 through 4; the default value is 0 and creates no loopback devices. You enable CoS by configuring the flexible-queuing-mode option at the [edit chassis fpc 0] hierarchy level.


    The FPC reboots if you enable inline service interfaces or CoS or if you change the loopback device count.

  • DPDK support—vMX uses DPDK 2.x to support improved performance. Scheduling is performed in a separate core and the traffic load is balanced depending on the number of vCPUs for the VFP. If there are not enough cores available, scheduling shares the I/O core and impacts performance. For optimal performance, we recommend a minimum of (2.5 * number-of-ports) + 3 vCPUs for VFP (without CoS), a minimum of (3.5 * number-of-ports) + 3 vCPUs for VFP (with CoS), and 1G Huge Pages. You must set up Huge Pages when preparing the Ubuntu host.

  • Flow caching is enabled for L2TP tunnel interfaces—Flow caching is automatically enabled for L2TP tunnel interfaces.

  • Red Hat Enterprise Linux support—vMX can be installed on a host running KVM on Red Hat Enterprise Linux 7.2 operating system. You must prepare the host before installing vMX.

  • Red Hat OpenStack Platform support—Red Hat OpenStack Platform 8 is supported.

  • Virtual broadband network gateway—Using vMX, you can deploy a virtual broadband network gateway (vBNG) on x86 servers to terminate broadband subscribers. vBNG supports most of the subscriber management features available with Junos OS Release 17.1 on MX Series routers.

    vBNG runs on vMX, so it has similar exceptions; the following subscriber management features available on MX Series routers are not supported for vBNG:

    • High availability features such as hot-standby backup for enhanced subscriber management and MX Series Virtual Chassis.

    To deploy a vBNG instance, you must purchase these licenses:

    • vMX PREMIUM application package license with 1 Gbps, 5 Gbps, 10 Gbps, or 40 Gbps bandwidth

    • vBNG subscriber scale license with 1000, 10 thousand, 100 thousand, or 1 million subscriber sessions for one of these tiers:




      L2TP features including L2TP LNS services, secure policy, service activation and deactivation


      Features in the Introductory tier, and DHCP subscriber services, PPP/LAC subscriber services, DHCP relay and DHCP local server


      Features in the Preferred tier, and pseudowire ingress termination

      With the appropriate vMX PREMIUM license, you can evaluate vBNG without a vBNG subscriber scale license for 30 days. After 30 days, you are limited to 10 subscriber sessions.

    [See Junos OS Broadband Subscriber Management and Services Library.]