Description

On M320 Series routers, only two of the four ports are enabled on some of the T3, E3, and OC3 PICs after upgrading to a release that has the fix for PR1129778 .

This article gives the reason and also the configuration using which this setting can be modified.

 

Symptoms

After upgrading to a release containing the fix for PR1129778 , only two of the four ports (the even numbered ports) are available for configuration on some of the T3, E3, and OC3 PICs on M320 routers, whereas the same hardware and configuration had all the four ports available prior to the upgrade.

 

Solution

Prior to releases containing the fix for PR1129778 , restricted queue PICs with no max-queues-per-interface configuration would boot up by default with a maximum of four queues per port and all four ports would be enabled. After upgrading to a release containing the fix, restricted queue PICs boot up with a maximum of eight queues per port due to a change in default behavior. Further, only ports 0 and 2 are available for use, whereas no interfaces can be configured on ports 1 and 3.

The change introduced in the default behavior for restricted queue PICs through the fix for PR1129778 caused the same hardware and configuration to behave differently after the upgrade.

The following PICs are restricted queue PICs:

  • "4x OC-3 SONET" or "4x STM-1 SDH"

  • "4x OC-3 1x OC-12 SFP" or "4x STM-1 1x STM-4 SFP"

  • "4x T3"

  • "4x E3"

 

To use all the four ports after upgrade, add the chassis fpc <> pic <> max-queues-per-interface 4 configuration to enable all the four ports with four queues per port. See also Configuring the Junos OS to Support Eight Queues on IQ Interfaces for T Series and M320 Routers .

For example, with the following hardware:

FPC 4            REV 03   710-013038   JL9916            M320 FPC Type 1
  CPU            REV 04   710-009141   JM3907            M320 FPC CPU
  PIC 0          REV 06   750-003065   HN3638            4x T3
  MMB 1          REV 03   710-010556   JJ9200            MMB-1M-288mbit
 

When you use Junos OS 11.4R6-S2, which does not have the fix for PR1129778:

labroot@rtr-re0> show interfaces extensive t3-4/0/* | no-more  <<< Shows all the 4 ports on the PIC
Physical interface: t3-4/0/0, Enabled, Physical link is Up  <<<< Port 0
  ..
  Egress queues: 8 supported, 4 in use <<< 4 queues are in use by default. 
  Queue counters:       Queued packets  Transmitted packets      Dropped packets
    0 P8-BE, P4-H2                   0                    0                    0
    1 P7-L2, P3-NC                   0                    0                    0
    2 P6-AF, P2-H1                   0                    0                    0
    3 P5-L1, P1-EF                   0                    0                    0
  Queue number:         Mapped forwarding classes
    0                   P8-BE, P4-H2
    1                   P7-L2, P3-NC
    2                   P6-AF, P2-H1
    3                   P5-L1, P1-EF
  
Physical interface: t3-4/0/1, Enabled, Physical link is Up   <<< Port 1
  ...
  Egress queues: 8 supported, 4 in use <<< 4 queues are in use by default. 
  Queue counters:       Queued packets  Transmitted packets      Dropped packets
    0 P8-BE, P4-H2                   0                    0                    0
    1 P7-L2, P3-NC                   0                    0                    0
    2 P6-AF, P2-H1                   0                    0                    0
    3 P5-L1, P1-EF                   0                    0                    0
  Queue number:         Mapped forwarding classes
    0                   P8-BE, P4-H2
    1                   P7-L2, P3-NC
    2                   P6-AF, P2-H1
    3                   P5-L1, P1-EF
  
Physical interface: t3-4/0/2, Enabled, Physical link is Down   <<< Port 2
  ...
  Egress queues: 8 supported, 4 in use <<< 4 queues are in use by default 
  Queue counters:       Queued packets  Transmitted packets      Dropped packets
    0 P8-BE, P4-H2                   0                    0                    0
    1 P7-L2, P3-NC                   0                    0                    0
    2 P6-AF, P2-H1                   0                    0                    0
    3 P5-L1, P1-EF                   0                    0                    0
  Queue number:         Mapped forwarding classes
    0                   P8-BE, P4-H2
    1                   P7-L2, P3-NC
    2                   P6-AF, P2-H1
    3                   P5-L1, P1-EF
 
Physical interface: t3-4/0/3, Administratively down, Physical link is Down   <<< Port 3
 ...
  Egress queues: 8 supported, 4 in use <<<< 4 queues are in use by default. 
  Queue counters:       Queued packets  Transmitted packets      Dropped packets
    0 P8-BE, P4-H2                   0                    0                    0
    1 P7-L2, P3-NC                   0                    0                    0
    2 P6-AF, P2-H1                   0                    0                    0
    3 P5-L1, P1-EF                   0                    0                    0
  Queue number:         Mapped forwarding classes
    0                   P8-BE, P4-H2
    1                   P7-L2, P3-NC
    2                   P6-AF, P2-H1
    3                   P5-L1, P1-EF
 ...
 

After upgrading to Junos OS 15.1R4-S7, which has the fix for the above PR:

labroot@rtr-re0> show interfaces extensive t3-4/0/*  <<< Only 2 ports that are even numbered are displayed and available. 
Physical interface: t3-4/0/0, Enabled, Physical link is Up   <<< Port 0
 ...

  Egress queues: 8 supported, 8 in use <<<< 8 queues are in use by default.
  Queue counters:       Queued packets  Transmitted packets      Dropped packets
    0                                0                    0                    0
    1                                0                    0                    0
    2                                0                    0                    0
    3                                0                    0                    0
    4                                0                    0                    0
    5                                0                    0                    0
    6                                0                    0                    0
    7                                0                    0                    0
  Queue number:         Mapped forwarding classes
    0                   P8-BE
    1                   P7-L2
    2                   P6-AF
    3                   P5-L1
    4                   P4-H2
    5                   P3-NC
    6                   P2-H1
    7                   P1-EF
 
Physical interface: t3-4/0/2, Enabled, Physical link is Down   <<< Port 2
  ..
  Egress queues: 8 supported, 8 in use <<< 8 queues are in use by default.
  Queue counters:       Queued packets  Transmitted packets      Dropped packets
    0                                0                    0                    0
    1                                0                    0                    0
    2                                0                    0                    0
    3                                0                    0                    0
    4                                0                    0                    0
    5                                0                    0                    0
    6                                0                    0                    0
    7                                0                    0                    0
  Queue number:         Mapped forwarding classes
    0                   P8-BE
    1                   P7-L2
    2                   P6-AF
    3                   P5-L1
    4                   P4-H2
    5                   P3-NC           
    6                   P2-H1
    7                   P1-EF
 

After adding the below configuration and manually restarting PIC 0 on FPC 4, you can see that all the four ports, each with four queues are enabled:

chassis {
      fpc 4 {
            pic 0 {
               max-queues-per-interface 4;
            }   
      }
}
 
labroot@rtr-re0> show interfaces extensive t3-4/0/*  <<< Shows all the 4 ports on the PIC
Physical interface: t3-4/0/0, Enabled, Physical link is Up   <<< Port 0
  ..
  Egress queues: 8 supported, 4 in use <<< 4 queues are in use through the modified configuration.
  Queue counters:       Queued packets  Transmitted packets      Dropped packets
    0                                0                    0                    0
    1                                0                    0                    0
    2                                0                    0                    0
    3                                0                    0                    0
  Queue number:         Mapped forwarding classes
    0                   P8-BE, P4-H2
    1                   P7-L2, P3-NC
    2                   P6-AF, P2-H1
    3                   P5-L1, P1-EF
  
Physical interface: t3-4/0/1, Enabled, Physical link is Up   <<<< Port 1
..
  Egress queues: 8 supported, 4 in use <<< 4 queues are in use through the modified configuration.
  Queue counters:       Queued packets  Transmitted packets      Dropped packets
    0                                0                    0                    0
    1                                0                    0                    0
    2                                0                    0                    0
    3                                0                    0                    0
  Queue number:         Mapped forwarding classes
    0                   P8-BE, P4-H2
    1                   P7-L2, P3-NC
    2                   P6-AF, P2-H1
    3                   P5-L1, P1-EF
  
Physical interface: t3-4/0/2, Enabled, Physical link is Down   <<<< Port 2
 ..
  Egress queues: 8 supported, 4 in use <<< 4 queues are in use through the modified configuration.
  Queue counters:       Queued packets  Transmitted packets      Dropped packets
    0                                0                    0                    0
    1                                0                    0                    0
    2                                0                    0                    0
    3                                0                    0                    0
  Queue number:         Mapped forwarding classes
    0                   P8-BE, P4-H2
    1                   P7-L2, P3-NC
    2                   P6-AF, P2-H1
    3                   P5-L1, P1-EF
  
Physical interface: t3-4/0/3, Administratively down, Physical link is Down   <<< Port 3
 ..
  Egress queues: 8 supported, 4 in use <<< 4 queues are in use through the modified configuration.
  Queue counters:       Queued packets  Transmitted packets      Dropped packets
    0                                0                    0                    0
    1                                0                    0                    0
    2                                0                    0                    0
    3                                0                    0                    0
  Queue number:         Mapped forwarding classes
    0                   P8-BE, P4-H2
    1                   P7-L2, P3-NC
    2                   P6-AF, P2-H1
    3                   P5-L1, P1-EF