Support Support Downloads Knowledge Base Case Manager My Juniper Community

Knowledge Base

Search our Knowledge Base sites to find answers to your questions.

Ask All Knowledge Base Sites All Knowledge Base Sites JunosE Defect (KA)Knowledge BaseSecurity AdvisoriesTechnical BulletinsTechnotes Sign in to display secure content and recently viewed articles

[QFX] Varying mc-ae init-delay time minimizes traffic loss under large scale mc-ae deployment when MC-LAG peer reboots

0

0

Article ID: KB32698 KB Last Updated: 29 May 2018Version: 1.0
Summary:

The init delay time specifies the number of seconds by which to delay bringing up the MC-LAG interface back to the up state when the MC-LAG peer is rebooted. By delaying the bring-up of the interface until after the protocol convergence, you can prevent packet loss during the recovery of failed links and devices.

With same init-delay-time value on multiple mc-ae interfaces, during booting up, MC-LAG peer tries to perform the following at the same time:

  • Bring up all mc-ae interfaces 
  • Establish LACP on all interfaces at the same time with peer access devices
  • Share all mc-ae interfaces info to MCLAG peer device.

Due to many operations being performed at the same time when a MC-LAG peer boots up, more CPU cycles are needed. Under this high CPU condition, there is possibility of a race condition like LACPD at Control Plane for all mc-ae interfaces might send CD to peer access device. However, TRUNK enable at PFE is still processing for some interfaces, which leads to traffic loss on mc-ae interfaces, and are not yet completely programed as TRUNK enable in PFE. Also, LACP establishment of mc-ae interfaces and sharing mc-ae interfaces status with peer MC-LAG devices using ICCP can be raced.

 

Solution:

To avoid this, it is recommended to have a different value for each mc-ae interface in case of scaled setup.

Example:

set interfaces ae10 aggregated-ether-options mc-ae init-delay-time 240

set interfaces ae11 aggregated-ether-options mc-ae init-delay-time 245

set interfaces ae12 aggregated-ether-options mc-ae init-delay-time 250

set interfaces ae13 aggregated-ether-options mc-ae init-delay-time 255

set interfaces ae14 aggregated-ether-options mc-ae init-delay-time 260

set interfaces ae15 aggregated-ether-options mc-ae init-delay-time 265

set interfaces ae16 aggregated-ether-options mc-ae init-delay-time 270

set interfaces ae17 aggregated-ether-options mc-ae init-delay-time 275

set interfaces ae18 aggregated-ether-options mc-ae init-delay-time 280

set interfaces ae19 aggregated-ether-options mc-ae init-delay-time 285

set interfaces ae20 aggregated-ether-options mc-ae init-delay-time 290

set interfaces ae21 aggregated-ether-options mc-ae init-delay-time 295

set interfaces ae22 aggregated-ether-options mc-ae init-delay-time 300

set interfaces ae23 aggregated-ether-options mc-ae init-delay-time 305

set interfaces ae24 aggregated-ether-options mc-ae init-delay-time 310

set interfaces ae25 aggregated-ether-options mc-ae init-delay-time 315

set interfaces ae26 aggregated-ether-options mc-ae init-delay-time 320

set interfaces ae27 aggregated-ether-options mc-ae init-delay-time 325

set interfaces ae28 aggregated-ether-options mc-ae init-delay-time 330

set interfaces ae29 aggregated-ether-options mc-ae init-delay-time 335

set interfaces ae30 aggregated-ether-options mc-ae init-delay-time 340

set interfaces ae31 aggregated-ether-options mc-ae init-delay-time 345

set interfaces ae32 aggregated-ether-options mc-ae init-delay-time 350

set interfaces ae33 aggregated-ether-options mc-ae init-delay-time 355

set interfaces ae34 aggregated-ether-options mc-ae init-delay-time 360

set interfaces ae35 aggregated-ether-options mc-ae init-delay-time 365

set interfaces ae36 aggregated-ether-options mc-ae init-delay-time 370

set interfaces ae37 aggregated-ether-options mc-ae init-delay-time 375

set interfaces ae38 aggregated-ether-options mc-ae init-delay-time 380

set interfaces ae39 aggregated-ether-options mc-ae init-delay-time 385

set interfaces ae40 aggregated-ether-options mc-ae init-delay-time 390

set interfaces ae41 aggregated-ether-options mc-ae init-delay-time 395

set interfaces ae42 aggregated-ether-options mc-ae init-delay-time 400

set interfaces ae43 aggregated-ether-options mc-ae init-delay-time 405

set interfaces ae44 aggregated-ether-options mc-ae init-delay-time 410

set interfaces ae45 aggregated-ether-options mc-ae init-delay-time 415

set interfaces ae46 aggregated-ether-options mc-ae init-delay-time 420

set interfaces ae47 aggregated-ether-options mc-ae init-delay-time 425

set interfaces ae48 aggregated-ether-options mc-ae init-delay-time 430

set interfaces ae49 aggregated-ether-options mc-ae init-delay-time 435

 

Related Links

Comment on this article > Affected Products Browse the Knowledge Base for more articles related to these product categories. Select a category to begin.

Getting Up and Running with Junos

Getting Up and Running with Junos Security Alerts and Vulnerabilities Product Alerts and Software Release Notices Problem Report (PR) Search Tool EOL Notices and Bulletins JTAC User Guide Customer Care User Guide Pathfinder SRX High Availability Configurator SRX VPN Configurator Training Courses and Videos End User Licence Agreement Global Search