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[MX/PTX] Command 'show interfaces fxp0' always show '1000mbps' speed and 'Full-duplex' mode even though it's wrong

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Article ID: KB36318 KB Last Updated: 24 Nov 2020Version: 1.0
Summary:

On MX and PTX platforms with Next Generation Routing Engines (NG-RE: RE-MX-X6, RE-MX-X8, and RE-PTX-X8) installed, the CLI command 'show vmhost management-if' must be used to find the correct management port link speed and mode. This is because running 'show interfaces fxp0' on NG-RE always show 1000mbps speed and Full-duplex mode, regardless of the actual link speed and mode.

This article explains why the command, 'show interfaces fxp0' should not be used on MX and PTX platforms with NG-RE installed.

Symptoms:

Test topology:

mx204 MGMT fxp0 --------- LAN UTP ---------- ge-1/2/0 mx80 fxp0 --- LAN UTP --- Local PC
        COM  -------------- Serial console -------------------------------------- COM

test@mx80> show chassis hardware
Hardware inventory:
Item             Version  Part number  Serial number     Description
Chassis                                E4244             MX80
Midplane         REV 07   711-031594   YL2374            MX80
PEM 0            Rev 03   740-028288   UG00858           AC Power Entry Module
PEM 1            Rev 04   740-028288   WF05473           AC Power Entry Module
Routing Engine            BUILTIN      BUILTIN           Routing Engine
TFEB 0                    BUILTIN      BUILTIN           Forwarding Engine Processor
  QXM 0          REV 05   711-028408   YM1313            MPC QXM
FPC 0                     BUILTIN      BUILTIN           MPC BUILTIN
  MIC 0                   BUILTIN      BUILTIN           4x 10GE XFP
    PIC 0                 BUILTIN      BUILTIN           4x 10GE XFP
FPC 1                     BUILTIN      BUILTIN           MPC BUILTIN
  MIC 1          REV 26   750-028392   ZN2537            3D 20x 1GE(LAN) SFP
    PIC 2                 BUILTIN      BUILTIN           10x 1GE(LAN) SFP
      Xcvr 0     REV 02   740-013111   I363002           SFP-T <-- This is connected to mx204 MGMT fxp0
    PIC 3                 BUILTIN      BUILTIN           10x 1GE(LAN) SFP
Fan Tray                                                 Fan Tray

Test 1

MX204 MGMT fxp0 is Up with 1G and Full-duplex by auto-negotiation.

When MX80 ge-1/2/0 is auto-negotiation configured, MGMT port fxp0 is Up with 1000mbps and Full-duplex.
Both commands, 'show interfaces fxp0' and 'show vmhost management-if' show 1000mbps and Full-duplex.

test@mx80> show configuration interfaces ge-1/2/0
gigether-options {
    auto-negotiation;
}

test@mx80> show interfaces ge-1/2/0 media
Physical interface: ge-1/2/0, Enabled, Physical link is Up
  Interface index: 152, SNMP ifIndex: 521
  Link-level type: Ethernet, MTU: 1514, MRU: 1522, LAN-PHY mode,
  Speed: 1000mbps, BPDU Error: None, Loop Detect PDU Error: None,
  Ethernet-Switching Error: None, MAC-REWRITE Error: None, Loopback: Disabled,
  Source filtering: Disabled, Flow control: Enabled, Auto-negotiation: Enabled,
  Remote fault: Online
  Pad to minimum frame size: Disabled
  Device flags   : Present Running
  Interface flags: SNMP-Traps Internal: 0x0
  Link flags     : None
  CoS queues     : 8 supported, 8 maximum usable queues
  Current address: 80:71:1f:c5:b1:78, Hardware address: 80:71:1f:c5:b1:78
  Last flapped   : 2020-11-06 16:11:48 JST (00:01:28 ago)
  Input rate     : 0 bps (0 pps)
  Output rate    : 0 bps (0 pps)
  Active alarms  : None
  Active defects : None
  PCS statistics                      Seconds
    Bit errors                             0
    Errored blocks                         0
  Ethernet FEC statistics              Errors
    FEC Corrected Errors                    0
    FEC Uncorrected Errors                  0
    FEC Corrected Errors Rate               0
    FEC Uncorrected Errors Rate             0
  MAC statistics:
    Input bytes: 282, Input packets: 2, Output bytes: 0, Output packets: 0
  Filter statistics:
    Filtered packets: 2, Padded packets: 0, Output packet errors: 0
  Autonegotiation information:
    Negotiation status: Complete
    Link partner:
        Link mode: Full-duplex, Flow control: Symmetric/Asymmetric,
        Remote fault: OK, Link partner Speed: 1000 Mbps
    Local resolution:
        Flow control: Symmetric, Remote fault: Link OK,
        Local link Speed: 1000 Mbps, Link mode: Full-duplex
  Interface transmit statistics: Disabled

lab@mx204> show configuration groups jnpr-poc interfaces fxp0
unit 0 {
    family inet {
        address 172.27.115.99/22;
    }
}

lab@mx204> show interfaces fxp0 media
Physical interface: fxp0, Enabled, Physical link is Up
  Interface index: 64, SNMP ifIndex: 1
  Type: Ethernet, Link-level type: Ethernet, MTU: 1514, Speed: 1000mbps
  Device flags   : Present Running
  Interface flags: SNMP-Traps
  Link type      : Full-Duplex
  Current address: e4:fc:82:45:80:42, Hardware address: e4:fc:82:45:80:42
  Last flapped   : 2020-11-06 16:11:47 JST (00:03:49 ago)
    Input packets : 9847233
    Output packets: 7750

lab@mx204> show vmhost management-if
Administrative status: Up
Link status: Up
Link speed: 1000Mb/s
Link operational mode: Full
 

Test 2

MX204 MGMT fxp0 is Up with 1G and Full-duplex by no-auto-negotiation.

When mx80 ge-1/2/0 is no-auto-negotiation configured, MGMT port fxp0 is Up with 1000mbps and Full-duplex.
Both the commands, 'show interfaces fxp0' and 'show vmhost management-if' show 1000mbps and Full-duplex.

Note: Half-duplex mode with 1000mbps is not supported by any of the PHY chip vendors.

test@mx80> show configuration interfaces ge-1/2/0
gigether-options {
    no-auto-negotiation;
}

test@mx80> show interfaces ge-1/2/0 media
Physical interface: ge-1/2/0, Enabled, Physical link is Up
  Interface index: 152, SNMP ifIndex: 521
  Link-level type: Ethernet, MTU: 1514, MRU: 1522, LAN-PHY mode,
  Speed: 1000mbps, BPDU Error: None, Loop Detect PDU Error: None,
  Ethernet-Switching Error: None, MAC-REWRITE Error: None, Loopback: Disabled,
  Source filtering: Disabled, Flow control: Enabled, Auto-negotiation: Disabled,
  Remote fault: Online
  Pad to minimum frame size: Disabled
  Device flags   : Present Running
  Interface flags: SNMP-Traps Internal: 0x0
  Link flags     : None
  CoS queues     : 8 supported, 8 maximum usable queues
  Current address: 80:71:1f:c5:b1:78, Hardware address: 80:71:1f:c5:b1:78
  Last flapped   : 2020-11-06 17:15:01 JST (00:00:20 ago)
  Input rate     : 0 bps (0 pps)
  Output rate    : 0 bps (0 pps)
  Active alarms  : None
  Active defects : None
  PCS statistics                      Seconds
    Bit errors                             0
    Errored blocks                         0
  Ethernet FEC statistics              Errors
    FEC Corrected Errors                    0
    FEC Uncorrected Errors                  0
    FEC Corrected Errors Rate               0
    FEC Uncorrected Errors Rate             0
  MAC statistics:
    Input bytes: 3588, Input packets: 41, Output bytes: 0, Output packets: 0
  Filter statistics:
    Filtered packets: 40, Padded packets: 0, Output packet errors: 0
  Autonegotiation information:
    Negotiation status: Complete
  Interface transmit statistics: Disabled

lab@mx204> show interfaces fxp0 media
Physical interface: fxp0, Enabled, Physical link is Up
  Interface index: 64, SNMP ifIndex: 1
  Type: Ethernet, Link-level type: Ethernet, MTU: 1514, Speed: 1000mbps
  Device flags   : Present Running
  Interface flags: SNMP-Traps
  Link type      : Full-Duplex
  Current address: e4:fc:82:45:80:42, Hardware address: e4:fc:82:45:80:42
  Last flapped   : 2020-11-06 17:15:00 JST (00:02:49 ago)
    Input packets : 18976602
    Output packets: 28435

lab@mx204> show vmhost management-if
Administrative status: Up
Link status: Up
Link speed: 1000Mb/s
Link operational mode: Full

Test 3

MX204 MGMT fxp0 is Up with 100m and Full-duplex by auto-negotiation.
When mx80 ge-1/2/0 is speed 100m and auto-negotiation configured, MGMT port fxp0 is Up with 100mbps and Full-duplex.
The command, 'show vmhost management-if' correctly shows 100mbps and Full-duplex, but the command, 'show interfaces fxp0' incorrectly shows1000mbps and Full-duplex.

test@mx80> show configuration interfaces ge-1/2/0
speed 100m;
gigether-options {
    auto-negotiation;
}

test@mx80> show interfaces ge-1/2/0 media
Physical interface: ge-1/2/0, Enabled, Physical link is Up
  Interface index: 152, SNMP ifIndex: 521
  Link-level type: Ethernet, MTU: 1514, MRU: 1522, LAN-PHY mode, Speed: 100mbps,
  BPDU Error: None, Loop Detect PDU Error: None, Ethernet-Switching Error: None,
  MAC-REWRITE Error: None, Loopback: Disabled, Source filtering: Disabled,
  Flow control: Enabled, Auto-negotiation: Enabled, Remote fault: Online
  Pad to minimum frame size: Disabled
  Device flags   : Present Running
  Interface flags: SNMP-Traps Internal: 0x0
  Link flags     : None
  CoS queues     : 8 supported, 8 maximum usable queues
  Current address: 80:71:1f:c5:b1:78, Hardware address: 80:71:1f:c5:b1:78
  Last flapped   : 2020-11-06 16:17:34 JST (00:00:12 ago)
  Input rate     : 0 bps (0 pps)
  Output rate    : 0 bps (0 pps)
  Active alarms  : None
  Active defects : None
  PCS statistics                      Seconds
    Bit errors                             0
    Errored blocks                         0
  Ethernet FEC statistics              Errors
    FEC Corrected Errors                    0
    FEC Uncorrected Errors                  0
    FEC Corrected Errors Rate               0
    FEC Uncorrected Errors Rate             0
  MAC statistics:
    Input bytes: 1222, Input packets: 12, Output bytes: 0, Output packets: 0
  Filter statistics:
    Filtered packets: 12, Padded packets: 0, Output packet errors: 0
  Autonegotiation information:
    Negotiation status: Complete
    Link partner:
        Link mode: Full-duplex, Flow control: Symmetric/Asymmetric,
        Remote fault: OK, Link partner Speed: 100 Mbps
    Local resolution:
        Flow control: Symmetric, Remote fault: Link OK,
        Local link Speed: 1000 Mbps, Link mode: Full-duplex
  Interface transmit statistics: Disabled

lab@mx204> show interfaces fxp0 media
Physical interface: fxp0, Enabled, Physical link is Up
  Interface index: 64, SNMP ifIndex: 1
  Type: Ethernet, Link-level type: Ethernet, MTU: 1514, Speed: 1000mbps
  Device flags   : Present Running
  Interface flags: SNMP-Traps
  Link type      : Full-Duplex
  Current address: e4:fc:82:45:80:42, Hardware address: e4:fc:82:45:80:42
  Last flapped   : 2020-11-06 16:17:35 JST (00:01:50 ago)
    Input packets : 9847233
    Output packets: 7758

lab@mx204> show vmhost management-if
Administrative status: Up
Link status: Up
Link speed: 100Mb/s
Link operational mode: Full

Test 4

MX204 MGMT fxp0 is Up with 100m and Half-duplex by no-auto-negotiation.

When mx80 ge-1/2/0 is speed 100m and no-auto-negotiation configured, MGMT port fxp0 is Up with 100mbps and Half-duplex.
The command, 'show vmhost management-if' correctly shows 100mbps and Half-duplex, but the command, 'show interfaces fxp0' incorrectly shows 1000mbps and Full-duplex.

test@mx80> show configuration interfaces ge-1/2/0
speed 100m;
gigether-options {
    no-auto-negotiation;
}

test@mx80> show interfaces ge-1/2/0 media
Physical interface: ge-1/2/0, Enabled, Physical link is Up
  Interface index: 152, SNMP ifIndex: 521
  Link-level type: Ethernet, MTU: 1514, MRU: 1522, LAN-PHY mode, Speed: 100mbps,
  BPDU Error: None, Loop Detect PDU Error: None, Ethernet-Switching Error: None,
  MAC-REWRITE Error: None, Loopback: Disabled, Source filtering: Disabled,
  Flow control: Enabled, Auto-negotiation: Disabled, Remote fault: Online
  Pad to minimum frame size: Disabled
  Device flags   : Present Running
  Interface flags: SNMP-Traps Internal: 0x0
  Link flags     : None
  CoS queues     : 8 supported, 8 maximum usable queues
  Current address: 80:71:1f:c5:b1:78, Hardware address: 80:71:1f:c5:b1:78
  Last flapped   : 2020-11-06 17:19:11 JST (00:00:17 ago)
  Input rate     : 0 bps (0 pps)
  Output rate    : 0 bps (0 pps)
  Active alarms  : None
  Active defects : None
  PCS statistics                      Seconds
    Bit errors                             0
    Errored blocks                         0
  Ethernet FEC statistics              Errors
    FEC Corrected Errors                    0
    FEC Uncorrected Errors                  0
    FEC Corrected Errors Rate               0
    FEC Uncorrected Errors Rate             0
  MAC statistics:
    Input bytes: 3964, Input packets: 45, Output bytes: 0, Output packets: 0
  Filter statistics:
    Filtered packets: 44, Padded packets: 0, Output packet errors: 0
  Autonegotiation information:
    Negotiation status: Incomplete
  Interface transmit statistics: Disabled

lab@mx204> show interfaces fxp0 media
Physical interface: fxp0, Enabled, Physical link is Up
  Interface index: 64, SNMP ifIndex: 1
  Type: Ethernet, Link-level type: Ethernet, MTU: 1514, Speed: 1000mbps
  Device flags   : Present Running
  Interface flags: SNMP-Traps
  Link type      : Full-Duplex
  Current address: e4:fc:82:45:80:42, Hardware address: e4:fc:82:45:80:42
  Last flapped   : 2020-11-06 17:19:09 JST (00:02:21 ago)
    Input packets : 18976602
    Output packets: 28447

lab@mx204> show vmhost management-if
Administrative status: Up
Link status: Up
Link speed: 100Mb/s
Link operational mode: Half
 

Test 5

MX204 MGMT fxp0 is Up with 10m and Full-duplex by auto-negotiation.

When mx80 ge-1/2/0 is speed 10m and auto-negotiation configured, MGMT port fxp0 is Up with 10mbps and Full-duplex.
The command, 'show vmhost management-if' correctly shows 10mbps and Full-duplex, but the command, 'show interfaces fxp0' incorrectly shows 1000mbps and Full-duplex.

test@mx80> show configuration interfaces ge-1/2/0
speed 10m;
gigether-options {
    auto-negotiation;
}

test@mx80> show interfaces ge-1/2/0 media
Physical interface: ge-1/2/0, Enabled, Physical link is Up
  Interface index: 152, SNMP ifIndex: 521
  Link-level type: Ethernet, MTU: 1514, MRU: 1522, LAN-PHY mode, Speed: 10mbps,
  BPDU Error: None, Loop Detect PDU Error: None, Ethernet-Switching Error: None,
  MAC-REWRITE Error: None, Loopback: Disabled, Source filtering: Disabled,
  Flow control: Enabled, Auto-negotiation: Enabled, Remote fault: Online
  Pad to minimum frame size: Disabled
  Device flags   : Present Running
  Interface flags: SNMP-Traps Internal: 0x0
  Link flags     : None
  CoS queues     : 8 supported, 8 maximum usable queues
  Current address: 80:71:1f:c5:b1:78, Hardware address: 80:71:1f:c5:b1:78
  Last flapped   : 2020-11-06 16:20:51 JST (00:00:28 ago)
  Input rate     : 0 bps (0 pps)
  Output rate    : 0 bps (0 pps)
  Active alarms  : None
  Active defects : None
  PCS statistics                      Seconds
    Bit errors                             0
    Errored blocks                         0
  Ethernet FEC statistics              Errors
    FEC Corrected Errors                    0
    FEC Uncorrected Errors                  0
    FEC Corrected Errors Rate               0
    FEC Uncorrected Errors Rate             0
  MAC statistics:
    Input bytes: 2162, Input packets: 22, Output bytes: 0, Output packets: 0
  Filter statistics:
    Filtered packets: 22, Padded packets: 0, Output packet errors: 0
  Autonegotiation information:
    Negotiation status: Complete
    Link partner:
        Link mode: Full-duplex, Flow control: Symmetric/Asymmetric,
        Remote fault: OK, Link partner Speed: 10 Mbps
    Local resolution:
        Flow control: Symmetric, Remote fault: Link OK,
        Local link Speed: 1000 Mbps, Link mode: Full-duplex
  Interface transmit statistics: Disabled

lab@mx204> show interfaces fxp0 media
Physical interface: fxp0, Enabled, Physical link is Up
  Interface index: 64, SNMP ifIndex: 1
  Type: Ethernet, Link-level type: Ethernet, MTU: 1514, Speed: 1000mbps
  Device flags   : Present Running
  Interface flags: SNMP-Traps
  Link type      : Full-Duplex
  Current address: e4:fc:82:45:80:42, Hardware address: e4:fc:82:45:80:42
  Last flapped   : 2020-11-06 16:20:51 JST (00:01:22 ago)
    Input packets : 9847233
    Output packets: 7780

lab@mx204> show vmhost management-if
Administrative status: Up
Link status: Up
Link speed: 10Mb/s
Link operational mode: Full

Test 6

MX204 MGMT fxp0 is Up with 10m and Half-duplex by no-auto-negotiation

When mx80 ge-1/2/0 is speed 10m and no-auto-negotiation configured, MGMT port fxp0 is Up with 10mbps and Half-duplex.
The command, 'show vmhost management-if' correctly shows 10mbps and Half-duplex, but the command, 'show interfaces fxp0' incorrectly shows 1000mbps and Full-duplex.

test@mx80> show configuration interfaces ge-1/2/0
speed 10m;
gigether-options {
    no-auto-negotiation;
}

test@mx80> show interfaces ge-1/2/0 media
Physical interface: ge-1/2/0, Enabled, Physical link is Up
  Interface index: 152, SNMP ifIndex: 521
  Link-level type: Ethernet, MTU: 1514, MRU: 1522, LAN-PHY mode, Speed: 10mbps,
  BPDU Error: None, Loop Detect PDU Error: None, Ethernet-Switching Error: None,
  MAC-REWRITE Error: None, Loopback: Disabled, Source filtering: Disabled,
  Flow control: Enabled, Auto-negotiation: Disabled, Remote fault: Online
  Pad to minimum frame size: Disabled
  Device flags   : Present Running
  Interface flags: SNMP-Traps Internal: 0x0
  Link flags     : None
  CoS queues     : 8 supported, 8 maximum usable queues
  Current address: 80:71:1f:c5:b1:78, Hardware address: 80:71:1f:c5:b1:78
  Last flapped   : 2020-11-06 17:22:46 JST (00:00:17 ago)
  Input rate     : 0 bps (0 pps)
  Output rate    : 0 bps (0 pps)
  Active alarms  : None
  Active defects : None
  PCS statistics                      Seconds
    Bit errors                             0
    Errored blocks                         0
  Ethernet FEC statistics              Errors
    FEC Corrected Errors                    0
    FEC Uncorrected Errors                  0
    FEC Corrected Errors Rate               0
    FEC Uncorrected Errors Rate             0
  MAC statistics:
    Input bytes: 5210, Input packets: 63, Output bytes: 0, Output packets: 0
  Filter statistics:
    Filtered packets: 62, Padded packets: 0, Output packet errors: 0
  Autonegotiation information:
    Negotiation status: Incomplete
  Interface transmit statistics: Disabled

lab@mx204> show interfaces fxp0 media
Physical interface: fxp0, Enabled, Physical link is Up
  Interface index: 64, SNMP ifIndex: 1
  Type: Ethernet, Link-level type: Ethernet, MTU: 1514, Speed: 1000mbps
  Device flags   : Present Running
  Interface flags: SNMP-Traps
  Link type      : Full-Duplex
  Current address: e4:fc:82:45:80:42, Hardware address: e4:fc:82:45:80:42
  Last flapped   : 2020-11-06 17:22:46 JST (00:01:02 ago)
    Input packets : 18976602
    Output packets: 28459

lab@mx204> show vmhost management-if
Administrative status: Up
Link status: Up
Link speed: 10Mb/s
Link operational mode: Half
Solution:

On MX and PTX platforms with Next Generation Routing Engines (NG-RE : RE-MX-X6, RE-MX-X8, and RE-PTX-X8) installed, the command 'show vmhost management-if' must be used to find the correct MGMT port link speed and mode. This is because running the command 'show interfaces fxp0' on NG-RE always shows speed 1000mbps and mode Full-Duplex, regardless of the actual Link speed and mode.

Do not use the command, 'show interfaces fxp0' on MX and PTX platforms with NG-RE installed.

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