Description

This article explains when logical interface .16386 is created on EX and QFX Series switches. 
 

Solution

IFL *.16386 is created on 10G and 40G interfaces when an SFP module is inserted without any logical unit (IFL) configuration.

  • The default IFL (.16386) is added only when there is no other configuration on the interface.

  • The default IFL on the interfaces is to support VC auto-provisioning on (et-/xe-) interfaces.

Lab output

Interface without any configuration 

labroot@SWITCH-1# show interfaces xe-0/0/2

{master:0}[edit]
labroot@SWITCH-1# run show interfaces terse xe-0/0/2
Interface               Admin Link Proto    Local                 Remote
xe-0/0/2                up    up
xe-0/0/2.16386          up    up

Interface with family ethernet-switching configuration. 

labroot@SWITCH-1# show interfaces xe-0/0/2
unit 0 {
    family ethernet-switching;
}
 
{master:0}[edit]
labroot@SWITCH-1# run show interfaces terse xe-0/0/2
Interface               Admin Link Proto    Local                 Remote
xe-0/0/2                up    up
xe-0/0/2.0              up    up   eth-switch
 In addition, the default IFL (.16386) is skipped in the following conditions:

  • When the interface has VLAN tagging

  • If the interface is a member of an AE interface

  • If the interface is channelized

 

Modification History

2022-03-22: slight modification to first list item in the solution section.
2020-02-18: No changes made. Explanation is still valid as tested on 18.1R3-S7.1