Description

This article explains why VT IFD/IFL is created and logical unit changes each time the VT interface is created.

 

Symptoms

- VT IFD is created when the tunnel service is enabled.

 

labroot@R1_re0> show configuration chassis

fpc 0 {

  pic 0 {

    tunnel-services;

  }

}

 

 

labroot@R1_re0> show interfaces terse vt*

Interface        Admin Link Proto  Local         Remote

vt-0/0/0        up  up

vt-0/0/1        up  up

vt-0/0/2        up  up

vt-0/0/3        up  up

 

 

- RSVP creates VT ifl by default, if tunnel service is enabled.

 

 

labroot@R1_re0# show protocols rsvp

interface et-0/0/0.0;

 

 

labroot@R1_re0# run show interfaces terse vt*

Interface        Admin Link Proto  Local         Remote

vt-0/0/0        up  up

vt-0/0/0.2097155    up  up  inet

                  mpls

vt-0/0/1        up  up

vt-0/0/1.2097154    up  up  inet

                  mpls

vt-0/0/2        up  up

vt-0/0/2.2097153    up  up  inet

                  mpls

vt-0/0/3        up  up

vt-0/0/3.2097152    up  up  inet

 

 

- Deactivate/activate RSVP would recreate VT IFLs, and these logical units are assigned sequentially each time the VT interface is recreated.

 

Sep 5 20:03:20.288 R1_re mgd[32206]: UI_CMDLINE_READ_LINE: User 'labroot', command 'set protocols rsvp interface et-0/0/0 '

Sep 5 20:03:21.750 R1_re mgd[32206]: UI_CMDLINE_READ_LINE: User 'labroot', command 'commit '

Sep 5 20:03:53.360 R1_re mib2d[18969]: SNMP_TRAP_LINK_UP: ifIndex 780, ifAdminStatus up(1), ifOperStatus up(1), ifName vt-0/0/3.2097152

Sep 5 20:03:53.361 R1_re mib2d[18969]: SNMP_TRAP_LINK_UP: ifIndex 781, ifAdminStatus up(1), ifOperStatus up(1), ifName vt-0/0/2.2097153

Sep 5 20:03:53.361 R1_re mib2d[18969]: SNMP_TRAP_LINK_UP: ifIndex 782, ifAdminStatus up(1), ifOperStatus up(1), ifName vt-0/0/1.2097154

Sep 5 20:03:53.361 R1_re mib2d[18969]: SNMP_TRAP_LINK_UP: ifIndex 783, ifAdminStatus up(1), ifOperStatus up(1), ifName vt-0/0/0.2097155

 

Sep 5 20:18:13.382 R1_re mgd[32206]: UI_CMDLINE_READ_LINE: User 'labroot', command 'deactivate protocols rsvp '

Sep 5 20:18:13.976 R1_re mgd[32206]: UI_CMDLINE_READ_LINE: User 'labroot', command 'commit '

Sep 5 20:18:15.761 R1_re mib2d[18969]: SNMP_TRAP_LINK_DOWN: ifIndex 783, ifAdminStatus down(2), ifOperStatus down(2), ifName vt-0/0/0.2097155

Sep 5 20:18:15.761 R1_re mib2d[18969]: SNMP_TRAP_LINK_DOWN: ifIndex 782, ifAdminStatus down(2), ifOperStatus down(2), ifName vt-0/0/1.2097154

Sep 5 20:18:15.761 R1_re mib2d[18969]: SNMP_TRAP_LINK_DOWN: ifIndex 781, ifAdminStatus down(2), ifOperStatus down(2), ifName vt-0/0/2.2097153

Sep 5 20:18:15.761 R1_re mib2d[18969]: SNMP_TRAP_LINK_DOWN: ifIndex 780, ifAdminStatus down(2), ifOperStatus down(2), ifName vt-0/0/3.2097152

 

Sep 5 20:18:20.391 R1_re mgd[32206]: UI_CMDLINE_READ_LINE: User 'labroot', command 'rollback 1 '

Sep 5 20:18:23.836 R1_re mgd[32206]: UI_CMDLINE_READ_LINE: User 'labroot', command 'commit '

Sep 5 20:18:53.360 R1_re mib2d[18969]: SNMP_TRAP_LINK_UP: ifIndex 780, ifAdminStatus up(1), ifOperStatus up(1), ifName vt-0/0/3.2097156

Sep 5 20:18:53.360 R1_re mib2d[18969]: SNMP_TRAP_LINK_UP: ifIndex 781, ifAdminStatus up(1), ifOperStatus up(1), ifName vt-0/0/2.2097157

Sep 5 20:18:53.361 R1_re mib2d[18969]: SNMP_TRAP_LINK_UP: ifIndex 782, ifAdminStatus up(1), ifOperStatus up(1), ifName vt-0/0/1.2097158

Sep 5 20:18:53.361 R1_re mib2d[18969]: SNMP_TRAP_LINK_UP: ifIndex 783, ifAdminStatus up(1), ifOperStatus up(1), ifName vt-0/0/0.2097159

Solution

It is expected behavior.

Modification History

2024-09-06 : Article Created