Monitor Fast Ethernet and Gigabit Ethernet Interfaces
Learn how to effectively monitor Fast Ethernet and Gigabit Ethernet interfaces by following a comprehensive checklist, understanding key monitoring techniques, and reviewing fiber-optic Ethernet interface specifications.
Checklist to Monitor Fast Ethernet and Gigabit Ethernet Interfaces
Purpose
To monitor Fast Ethernet and Gigabit Ethernet interfaces and interface problems.
Action
It provides links and commands for monitoring Fast Ethernet and Gigabit Ethernet interfaces.
Tasks |
Command or Action |
|---|---|
| Monitor Fast Ethernet and Gigabit Ethernet Interfaces | |
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Display the Status of a Specific Fast Ethernet and Gigabit Ethernet Interface |
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Display Extensive Status for a Specific Fast Ethernet or Gigabit Ethernet Interface |
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Monitor Statistics for a Fast Ethernet or Gigabit Ethernet Interface |
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Meaning
You can use the commands to monitor and to display the configurations for Fast Ethernet and Gigabit Ethernet interfaces.
How to Monitor Fast Ethernet and Gigabit Ethernet Interfaces
Monitor the Fast Ethernet and Gigabit Ethernet interfaces to isolate interfaces related problems.
To monitor your Fast Ethernet and Gigabit Ethernet interfaces, follow these steps:
- Display the Status of Fast and Gigabit Ethernet Interfaces
- Display the Status of Gigabit Ethernet Interfaces
- Display the Status of a Specific Fast Ethernet and Gigabit Ethernet Interface
- Display Extensive Status for a Specific Fast Ethernet or Gigabit Ethernet Interface
- Monitor Statistics for a Fast Ethernet or Gigabit Ethernet Interface
Display the Status of Fast and Gigabit Ethernet Interfaces
Purpose
To display the status of Fast and Gigabit Ethernet interfaces, use the following Junos OS command-line interface (CLI) operational mode command:
Action
user@host> show interfaces terse (fe* | ge*)
Sample Output
user@host> show interfaces terse fe* Interface Admin Link Proto Local Remote fe-2/1/0 up up fe-2/1/0.0 up up inet 10.116.115.217/29 fe-3/0/2 up down fe-3/0/2.0 up down fe-3/0/3 up up fe-3/0/3.0 up up inet 192.168.223.65/30 fe-4/1/0 down up fe-4/1/0.0 up down inet 10.150.59.133/30 fe-4/1/1 up up fe-4/1/1.0 up up inet 10.150.59.129/30 fe-4/1/2 up down fe-4/1/2.0 up down
Meaning
The sample output lists only the Fast and Gigabit Ethernet interfaces. It shows the status of both the physical and logical interfaces.
Physical Interface |
Logical Interface |
Status Description |
|---|---|---|
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This interface has both the physical and logical links up and running. |
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This interface has the physical link down, the link layer down,
or both down |
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This interface is administratively disabled and the physical
link is healthy ( |
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This interface has both the physical and logical links down. |
Display the Status of Gigabit Ethernet Interfaces
Purpose
To display the status of Gigabit Ethernet interfaces, use the following Junos OS command-line interface (CLI) operational mode command:
Action
user@host> show interfaces terse ge* Interface Admin Link Proto Local Remote ge-2/2/0 down down ge-2/2/0.0 up down inet 65.113.23.105/30 ge-2/3/0 up up ge-2/3/0.0 up up inet 65.115.56.57/30 ge-3/1/0 up up ge-3/1/0.0 up up inet 65.115.56.193/30 ge-3/2/0 up down
Meaning
This sample output lists only the Gigabit Ethernet interfaces. It shows the status of both the physical and logical interfaces. See Table 3 for a description of what the output means.
Physical Interface |
Logical Interface |
Status Description |
|---|---|---|
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This interface is administratively disabled ( |
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This interface has both the physical and logical links up and running. |
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This interface has both the physical link and the logical interface down. |
Display the Status of a Specific Fast Ethernet and Gigabit Ethernet Interface
Purpose
To investigate the status of a specific Ethernet interface, use the following CLI command to view its details:
Action
user@host> show interfaces (fe-fpc/pic/port| ge-fpc/pic/port)
Sample Output 1
The following sample output is for a Fast Ethernet interface with the physical link up:
user@host> show interfaces fe-2/1/0
Physical interface: fe-2/1/0, Enabled, Physical link is Up
Interface index: 31, SNMP ifIndex: 35
Description: customer connection
Link-level type: Ethernet, MTU: 1514, Source filtering: Disabled
Speed: 100mbps, Loopback: Disabled, Flow control: Enabled
Device flags : Present Running
Interface flags: SNMP-Traps
Link flags : None
Current address: 00:90:69:86:71:1b, Hardware address: 00:90:69:86:71:1b
Input rate : 25768 bps (11 pps), Output rate: 1576 bps (3 pps)
Active alarms : None
Active defects : None
Logical interface fe-2/1/0.0 (Index 2) (SNMP ifIndex 43)
Flags: SNMP-Traps, Encapsulation: ENET2
Protocol inet, MTU: 1500, Flags: Is-Primary
Addresses, Flags: Is-Preferred Is-Primary
Destination: 10.116.151.218/29, Local: 10.119.115.217
Broadcast: 10.116.151.225
Sample Output 2
The following output is for a Gigabit Ethernet interface with the physical link up:
user@host> show interfaces ge-3/1/0
Physical interface: ge-3/1/0, Enabled, Physical link is Up
Interface index: 41, SNMP ifIndex: 55
Description: customer connection
Link-level type: Ethernet, MTU: 1514, Source filtering: Disabled
Speed: 1000mbps, Loopback: Disabled, Flow control: Enabled
Device flags : Present Running
Interface flags: SNMP-Traps
Link flags : None
Current address: 00:90:69:85:71:99, Hardware address: 00:90:69:85:71:99
Input rate : 7412216 bps (1614 pps), Output rate: 2431184 bps (1776 pps)
Active alarms : None
Active defects : None
Logical interface ge-3/1/0.0 (Index 11) (SNMP ifIndex 57)
Flags: SNMP-Traps, Encapsulation: ENET2
Protocol inet, MTU: 1500
Addresses, Flags: Is-Preferred Is-Primary
Destination: 10.117.65.192/30, Local: 10.115.65.193
Broadcast: 10.115.65.195
Meaning
The first line of sample output 1 and 2 shows that the physical link is up, indicating that it is healthy and can pass packets. Scroll through the output to check for any active alarms or defects. If alarms or defects are present, refer to Display Extensive Status Information for a Specific Fast Ethernet or Gigabit Ethernet Interface, for more detailed diagnostic information about the interface.
Display Extensive Status for a Specific Fast Ethernet or Gigabit Ethernet Interface
Purpose
To display extensive status information about a specific Fast Ethernet or Gigabit Ethernet interface, use the following Junos OS CLI operational mode command:
Action
user@host> show interfaces (fe-fpc/pic/port| ge-fpc/pic/port) extensive
Sample Output
The following sample output is for a Fast Ethernet interface:
user@router> show interfaces fe-1/3/3 extensive
Physical interface: fe-1/3/3, Enabled, Physical link is Up
Interface index: 47, SNMP ifIndex: 38
Description: Test
Link-level type: Ethernet, MTU: 1514, Source filtering: Disabled
Speed: 100mbps, Loopback: Disabled, Flow control: Enabled
Device flags : Present Running
Interface flags: SNMP-Traps
Link flags : None
Current address: 00:90:69:8d:2c:de, Hardware address: 00:90:69:8d:2c:de
Statistics last cleared: 2002-01-11 23:03:09 UTC (1w2d 23:54 ago)
Traffic statistics:
Input bytes : 373012658 0 bps
Output bytes : 153026154 1392 bps
Input packets: 1362858 0 pps
Output packets: 1642918 3 pps
Input errors:
Errors: 0 , Drops: 0, Framing errors: 0, Runts: 0, Policed discards: 503660
L3 incompletes: 1 , L2 channel errors: 0 , L2 mismatch timeouts: 0
FIFO errors: 0
Output errors:
Carrier transitions: 0, Errors: 0, Collisions: 0, Drops: 0, Aged packets: 0
HS link CRC errors: 0, FIFO errors: 0
Active alarms : None
Active defects : None
MAC statistics: Receive Transmit
Total octets 439703575 177452093
Total packets 1866532 1642916
Unicast packets 972137 1602563
Broadcast packets 30 2980
Multicast packets 894365 37373
CRC/Align errors 0 0
FIFO errors 0 0
MAC control frames 0 0
MAC pause frames 0 0
Oversized frames 0
Jabber frames 0
Fragment frames 0
VLAN tagged frames 0
Code violations 0
Filter statistics:
Input packet count 1866532
Input packet rejects 0
Input DA rejects 503674
Input SA rejects 0
Output packet count 1642916
Output packet pad count 0
Output packet error count 0
CAM destination filters: 5, CAM source filters: 0
Autonegotiation information:
Negotiation status: Complete, Link partner status: OK
Link partner: Full-duplex, Flow control: None
PFE configuration:
Destination slot: 1, Stream number: 15
CoS transmit queue bandwidth:
Queue0: 95, Queue1: 0, Queue2: 0, Queue3: 5
CoS weighted round-robin:
Queue0: 95, Queue1: 0, Queue2: 0, Queue3: 5
Logical interface fe-1/3/3.0 (Index 8) (SNMP ifIndex 69)
Description: Test
Flags: SNMP-Traps, Encapsulation: ENET2
Protocol inet, MTU: 1500, Flags: None
Addresses, Flags: Is-Preferred Is-Primary
Destination: 10.115.107.192/29, Local: 10.115.107.193
Broadcast: 10.115.107.199
Meaning
The sample output shows where the errors might be occurring and includes autonegotiation information.
Error |
Meaning |
|---|---|
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Discarded frames that were not recognized or were not of interest. |
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Packets for which the router could not find a valid logical interface. For example, the packet is for a virtual LAN (VLAN) that is not configured on the interface. |
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The maximum transmission unit (MTU) must match the interface of either the router at the remote end of the Fast Ethernet or Gigabit Ethernet link, or that of the switch. |
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Number of packets with a destination Media Access Control (MAC) address that is not on the accept list. It is normal to see this number increment. |
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Number of packets with a source MAC address that is not on the accept list. This number only increments when source MAC address filtering is configured. |
If the physical link is down, look at the active alarms and defects for the Fast Ethernet or Gigabit Ethernet interface and diagnose the Fast Ethernet or Gigabit Ethernet media accordingly. See Locate LINK Alarms and Counters for Fast and Gigabit Ethernet for an explanation of Fast Ethernet and Gigabit Ethernet alarms.
Error |
Meaning |
|---|---|
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The total number of packets received that had a length
(excluding framing bits, but including FCS octets) of between 64 and
1518 octets, inclusive, but had either a bad FCS with an integral
number of octets ( |
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The number of MAC control frames. |
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The number of MAC control frames with |
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The total number of packets received that were longer than 1518 octets (excluding framing bits, but including FCS octets), and had either an FCS error or an alignment error. Note that this definition of jabber is different from the definition in IEEE-802.3 section 8.2.1.5 (10BASE5) and section 10.3.1.4 (10BASE2). These documents define jabber as the condition where any packet exceeds 20 ms. The allowed range to detect jabber is between 20 ms and 150 ms. |
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The total number of packets received that were less than 64 octets in length (excluding framing bits, but including FCS octets), and had either an FCS error an alignment error. Note that it is entirely normal for fragment frames to increment because both runts (which are normal occurrences due to collisions) and noise hits are counted. |
Autonegotiation is the process that connected Ethernet interfaces
use to communicate the information necessary to interoperate. Table 6 explains the autonegotiation information
of the show interface interface-name extensive command output.
Autonegotiation Field Information |
Explanation |
|---|---|
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Ethernet interface has the speed or link mode configured. |
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Ethernet interface has the speed or link mode configured, or does not perform autonegotiation. |
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Ethernet interface is connected to a device that performs autonegotiation and the autonegotiation process completes successfully. |
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Depends on the capability of the attached Ethernet device. |
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Displays the types of flow control supported by the remote Ethernet device. |
Monitor Statistics for a Fast Ethernet or Gigabit Ethernet Interface
Purpose
To monitor statistics for a Fast Ethernet or Gigabit Ethernet interface, use the following Junos OS CLI operational mode command:
Action
user@host> monitor interface (fe-fpc/pic/port| ge-fpc/pic/port)
We recommend that you use the monitor interface fe-fpc/pic/port
or monitor interface ge-fpc/pic/port
command only for diagnostic purposes. Do not leave these commands on during normal
router operations because real-time monitoring of traffic consumes additional CPU and memory
resources.
Sample Output
The following sample output is for a Fast Ethernet interface:
user@host> monitor interface fe-2/1/0 Interface: fe-2/1/0, Enabled, Link is Up Encapsulation: Ethernet, Speed: 100mbps Traffic statistics: Current Delta Input bytes: 282556864218 (14208 bps) [40815] Output bytes: 42320313078 (384 bps) [890] Input packets: 739373897 (11 pps) [145] Output packets: 124798688 (1 pps) [14] Error statistics: Input errors: 0 [0] Input drops: 0 [0] Input framing errors: 0 [0] Policed discards: 6625892 [6] L3 incompletes: 75 [0] L2 channel errors: 0 [0] L2 mismatch timeouts: 0 [0] Carrier transitions: 1 [0] Output errors: 0 [0] Output drops: 0 [0] Aged packets: 0 [0] Active alarms : None Active defects: None Input MAC/Filter statistics: Unicast packets 464751787 [154] Packet error count 0 [0]
Meaning
Use the information from this command to help narrow down possible causes of an interface problem.
If you are accessing the router from the console connection, make sure you set the CLI
terminal type using the set cli terminal command.
The second column shows cumulative statistics since the last time you cleared them using the
clear interfaces statistics interface-name command. The third column
shows cumulative statistics since you ran the monitor interface
interface-name command. If input errors are increasing, follow these steps:
-
Check the cabling to the router and ask the carrier to verify the line’s integrity. Ensure you are using the correct cables for the interface port—single-mode fiber for a single-mode interface, and multimode fiber for a multimode interface.
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For fiber-optic connections, measure the received light level at the receiver end and ensure it meets the Ethernet interface’s specification.
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Measure the transmit light level on the Tx port to confirm it is within the specified range.
Fiber-Optic Ethernet Interface Specifications
Table 7 shows the specifications for fiber-optic interfaces.
Fiber-Optic Ethernet Interface |
Length |
Wavelength |
Average Launch Power |
Receiver Saturation |
Receiver Sensitivity |
|---|---|---|---|---|---|
| Gigabit Ethernet | |||||
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|||||
|
49.5-mile 70-km reach on 8.2-micrometer SMF |
1480 to 1580 nm |
-3 to +2 dBm |
-3 dBm |
-23 dBm (BER 1012) for SMF |
|
6.2-mile 10-km reach on 9/125-micrometer SMF 1804.5-ft 550-m reach on 62.5/125- and 50/125-micrometer MMF |
1270 to 1355 nm |
-11 to -3 dBm |
-3 dBm |
-19 dBm |
|
656-ft 200-m reach on 62.5/125-micrometer MMF 1640-ft 500-m reach on 50/125-micrometer MMF |
830 to 860 nm |
-9.5 to -4 dBm |
-3 dBm |
-17 dBm |
| Fast Ethernet 8-Port | |||||
|
1.24-mile 2-km reach on 62.5/125-micrometer MMF |
1270 to 1380 nm |
-20 to -14 dBm |
-14 dBm |
-34 dBm |