Specifications

High Availability (HA) and Resiliency

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MX Series Virtual Chassis support for multichassis link aggregation (MX Series

routers with MPCs)—Starting in Junos OS Release 13.3, an MX Series Virtual Chassis

supports configuration of multichassis link aggregation (MC-LAG). MC-LAG enables

a device to form a logical link aggregation group interface with two or more other

devices. The MC-LAG devices use the Inter-Chassis Communication Protocol (ICCP)

to exchange control information between two MC-LAG network devices.

When you configure MC-LAG with an MX Series Virtual Chassis, the link aggregation

group spans links to two Virtual Chassis configurations. Each Virtual Chassis consists

of two MX Series member routers that form a logical system managed as a single

network element. ICCP exchanges control information between the global master

router (VC-M) of the first Virtual Chassis and the VC-M of the second Virtual Chassis.

NOTE: Internet Group Management Protocol (IGMP) snooping is not

supported on MC-LAG interfaces in an MX Series Virtual Chassis.

[See Configuring Multichassis Link Aggregation.]

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TCP auto-merge support in nonstop active routing for short duration hold timers for

protocols (BGP, LDP) (kernel) (M Series, MX Series, and T Series)—Beginning with

Junos OS Release 13.3, TCP auto-merge support in nonstop active routing for protocols

(BGP, LDP) (kernel) is enabled on the M Series, MX Series, and T Series. Nonstop active

routing automerge is one of the kernel components of the socket replication. On

switchover, this component merges the socket pairs automatically from the secondary

to the primary Routing Engine. Currently, nonstop active routing switchover from

secondary to primary happens when rpd issues a merge call for each secondary socket

pair to merge them to a single socket, which can result in a delay. To avoid this delay,

this feature introduces an automerge module in the kernel that decouples the secondary

socket merge from rpd and automatically merges secondary sockets on switchover

so that the rpd high priority thread takes advantage of this and generates faster

keep-alive to sustain TCP connections on switchover.

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Nonstop active routing support for BGP addpath (M Series, MX Series, and T

Series)—Beginning in Junos OS Release 13.3, nonstop active routing support for BGP

addpath is available on the M Series, MX Series, and T Series. Nonstop active routing

support is enabled for the BGP addpath feature. After the nonstop active routing

switchover, addpath-enabled BGP sessions do not bounce. The secondary Routing

Engine maintains the addpath advertisement state before the nonstop active routing

switchover.

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Interchassis high availability provides stateful redundancy (MS-MPC and MS-MIC

interface cards on MX Series routers)—Starting with Release 13.3, Junos OS supports

stateful high availability (HA) to replicate flow states on an active MS-MPC or MS-MIC

service card to a standby MS-MPC or MS-MIC service card on a different chassis. This

enables the preservation of the state of the existing flows in case of a planned or

unplanned switchover.

New and Changed Features