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

[MX] How to identify whether "anchor PFE" is used for ae interface in OAM Protocols

0

0

Article ID: KB35276 KB Last Updated: 12 Nov 2019Version: 1.0
Summary:

In Bidirectional Forwarding Detection (BFD), periodic packet management (PPM) on the Routing Engine (RE) selects one of the Packet Forwarding Engines (PFEs) as an anchor-PFE when delegating a BFD session that is either a Multihop or Over an Aggregated Ethernet. The anchor PFE is then responsible for maintaining and transmit/receipt of the BFD session. Since the BFD packet can arrive on any interface for these sessions (MHOP or AE), having an anchor PFE ensures that the packets are absorbed at a common point where the sessions are maintained.

Given this benefit, can the anchor PFE feature be used for an AE interface in Operation, Administration, and Maintenance (OAM) Protocols? This article demonstrates the answer with an example.

Solution:
  1. For connectivity fault management (CFM), PPM runs in central mode. Therefore, there would be no “anchor PFE” in this scenario.
For example, here ae1.10 is running CFM:

labroot@jtac-mx480-r2006-re0> show oam ethernet connectivity-fault-management interfaces   
Interface                   Link      Status       Level  MEP         Neighbors
                                                          Identifier            
ae1.10, vlan 10             Up        Active       3      101         1        

The Distributed attribute is set to FALSE on ae1's member links, which indicates that PPM is running in central mode.


labroot@jtac-mx480-r2006-re0> show ppm adjacencies detail                                  
Protocol: CFM, Hold time: 300, IFL-index: 365
Distributed: FALSE   <<<

In Do-Dist thread:
CFM source key: MAID: 0404test0204test Level: 3 MEP-ID: 101 ack_rdi 0
Protocol: CFM, Hold time: 300, IFL-index: 371
Distributed: FALSE    <<<<

In Do-Dist thread:
CFM source key: MAID: 0405test10205test1 Level: 3 MEP-ID: 102 ack_rdi 0

Adjacencies: 2, Remote adjacencies: 0
  1. For link fault management (LFM), all AE child links handle PPM packets. Therefore, there would be no “anchor PFE” in this scenario as well.

For example, here ae19 is running LFM:

labroot@mxvc-r2028-r2029# run show oam ethernet link-fault-management ae19   
  Interface: ae19
    Status: Running, Discovery state: Send Any
    Transmit interval: 1000ms, PDU threshold: 3 frames, Hold time: 0ms

Here, xe-15/1/0 (ifl 970) and xe-16/1/0 (ifl 971) are child links of ae19, and both of them are handling PPM packets. In this case, PPM runs in distributed mode.


labroot@mxvc-r2028-r2029> show ppm adjacencies detail 
Protocol: LFM, Hold time: 3000, IFL-index: 970
Distributed: TRUE    <<<
Distribution handle: 14046, Distribution address: member1-fpc3

Protocol: LFM, Hold time: 3000, IFL-index: 971
Distributed: TRUE    <<<
Distribution handle: 14048, Distribution address: member1-fpc4

Adjacencies: 2, Remote adjacencies: 2

labroot@mxvc-r2028-r2029# run show interfaces ifl-index 970
  Logical interface xe-15/1/0.0 (Index 970) (SNMP ifIndex 2008)
...
    Protocol aenet, ae bundle: ae19.0
 
labroot@mxvc-r2028-r2029# run show interfaces ifl-index 971   
  Logical interface xe-16/1/0.0 (Index 971) (SNMP ifIndex 2009)
...
    Protocol aenet, ae bundle: ae19.0

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