Interface Management

The interface contains various information about the interface and the status of the interface. It is worth noting that when viewing interface information, multiple interfaces are displayed, so the command keyword is “interfaces” in plural form; while when configuring interfaces, they are configured one by one, so the keyword “interface” is used in singular form.

Interface Basic Configuration

show interface description

[Command]
show interface description

[Purpose]
Display individual interface description information

[View]
System view

[Use Cases]

sonic# show interface description
 Interface  Oper  Admin    Alias  Description
----------- ------ ------- ---------- -------------
 Ethernet1  down    up  Ethernet1      N/A
 Ethernet2  down    up  Ethernet2      N/A
 Ethernet3  down    up  Ethernet3      N/A
 Ethernet4  down    up  Ethernet4      N/A
 Ethernet5  down    up  Ethernet5      N/A
 Ethernet6  down    up  Ethernet6      N/A

show interface transceiver

[Command]
show interface transceiver {eeprom|lpmode|presence}

[Purpose]
Display of optical module information

[Parameter]

Parameter	Description
eeprom	Display interface transceiver EEPROM information
lpmode	Display interface transceiver low power mode
presence	Display module in-position information

[View]
System view

[Use Cases]

sonic# show interface transceiver eeprom
Ethernet48: SFP EEPROM Not detected
Ethernet49: SFP EEPROM detected
    Connector: LC
    Encoding: 64B/66B
    Extended Identifier: GBIC/SFP defined by twowire interface ID
    Extended RateSelect Compliance: Unspecified
    Identifier: SFP/SFP+/SFP28
    LengthOM3(UnitsOf10m): 0
    Nominal Bit Rate(100Mbs): 103
    Specification compliance:
        10GEthernetComplianceCode: 10G Base-LR
        FibreChannelLinkLength: Long distance (L)
        FibreChannelSpeed: 1200 MBytes/sec
        FibreChannelTechnology: Longwave Laser (LC)
        FibreChannelTransmissionMedia: Single Mode (SM)
    Vendor Date Code(YYYY-MM-DD Lot): 2018-07-21
    Vendor Name: OEM
    Vendor OUI: 00-00-00
    Vendor PN: TSSP31B33CDL10
    Vendor Rev: A
    Vendor SN: STST31182900045
sonic# show interface transceiver lpmode
Port    Low-power Mode
---------- ----------------
Ethernet1  Off
Ethernet2  Off
sonic# show interface transceiver presence
Port    Presence
---------- -----------
Ethernet1  Not present
Ethernet2  Not present

show interface port ethernet

[Command]
show interface port ethernet interface_id

[Purpose]
Display interface details

[View]
System view

[Use Cases]

sonic# show interface port
Ethernet1 is up, line protocol is down
Hardware is Eth
Interface index is 1
Description:
Mode of IPV4 address assignment: not-set
Mode of IPV6 address assignment: not-set
IP MTU 9216 bytes
LineSpeed 1G, Auto-negotiation off
Input statistics:
    0 packets, 0 octets
    0 Multicasts, 0 Broadcasts, 0 Unicasts
    0 error, 0 discarded
    0 ipv4Packets, 0 ipv4Octets
    0 ipv6Packets, 0 ipv6Octets
Output statistics:
    0 packets, 0 octets
    0 Multicasts, 0 Broadcasts, 0 Unicasts
    0 error, 0 discarded
    0 ipv4Octets, 0 ipv6Octets

show interface status

[Command]
show interface status

[Purpose]
Display interface staus

[View]
System view

[Use Cases]

sonic# show interface status
 Interface    Lanes      Speed  MTU  FEC  Alias  Oper  Admin      Type      Asym PFC
----------- ----------- ------- ----- ----- ------- ------ ------- -------------- ----------
 Ethernet1      0          25G  9216   rs    Y1  down    up SFP/SFP+/SFP28     N/A
 Ethernet2      1          10G  9216  none   Y2   up     up SFP/SFP+/SFP28     N/A
 Ethernet3      2          25G  9216   rs    Y3  down    up SFP/SFP+/SFP28     N/A
 Ethernet4      3          25G  9216   rs    Y4  down    up       N/A          N/A
 Ethernet5      4          25G  9216   rs    Y5  down    up       N/A          N/A
 Ethernet6      5          25G  9216   rs    Y6  down    up       N/A          N/A
 Ethernet7      6          25G  9216   rs    Y7  down    up       N/A          N/A
 Ethernet8      7          25G  9216   rs    Y8  down    up       N/A          N/A
 Ethernet9      8          25G  9216   rs    Y9  down    up       N/A          N/A
 Ethernet10     9          25G  9216   rs   Y10  down    up       N/A          N/A
…
 Ethernet46      45        25G  9216   rs   Y46  down    up       N/A          N/A
 Ethernet47      46        25G  9216   rs   Y47  down    up       N/A          N/A
 Ethernet48      47        25G  9216   rs   Y48  down    up       N/A          N/A
 Ethernet49 48,49,50,51   100G  9216   rs    C1  down    up       N/A          N/A
 Ethernet53 52,53,54,55   100G  9216   rs    C2  down    up       N/A          N/A
 Ethernet57 56,57,58,59   100G  9216   rs    C3  down    up       N/A          N/A
 Ethernet61 64,65,66,67   100G  9216   rs    C4  down    up       N/A          N/A
 Ethernet65 68,69,70,71   100G  9216   rs    C5  down    up       N/A          N/A
 Ethernet69 72,73,74,75   100G  9216   rs    C6  down    up       N/A          N/A
 Ethernet73 76,77,78,79   100G  9216   rs    C7  down    up       N/A          N/A
 Ethernet77 80,81,82,83   100G  9216   rs    C8  down    up       N/A          N/A

show counters interface

[Command]
show counters interface ethernet interface_id

[Purpose]
Show interface count

[Parameter]

Parameter	Description
interface_id	Interface id

[View]
System view

[Use Cases]

sonic# show counters interface
IFACE   STATE RX_OK RX_BPS RX_UTIL RX_ERR RX_DRP RX_OVR TX_OK TX_BPS TX_UTIL TX_ERR TX_DRP TX_OVR
-------------------------------------------------------------------------------------------------
Ethernet0  D    0   N/A    N/A     0      0      0      0     N/A    N/A      0      0     N/A
Ethernet1  U    0   N/A    N/A     0      0      0      27    N/A    N/A      0      0     N/A
Ethernet2  U    0   N/A    N/A     0      0      0      27    N/A    N/A      0      0     N/A
Ethernet3  U    0   N/A    N/A     0      0      0      35    N/A    N/A      0      0     N/A
Ethernet4  X    0   N/A    N/A     0      0      0      0     N/A    N/A      0      0     N/A

show link-flapping config

[Command]
show link-flapping config

[Purpose]
Show interface link-flapping configuration

[View]
System view

[Use Cases]

sonic# show link-flapping config
+-------------+----------+------------+-------------+------------+
| Port        | Detect   |   Interval |   Threshold | Action     |
+=============+==========+============+=============+============+
| Ethernet129 | enable   |         60 |           5 | error-down |
+-------------+----------+------------+-------------+------------+

show interface errdown

[Command]
show interface errdown

[Purpose]
Display the err-disable state of all interfaces

[View]
System view

[Notes]

Once an interface enters the errdown state, it cannot recover automatically. Manual restoration by executing the shutdown/no shutdown command in the interface view is required.

[Use Cases]

sonic# show interface errdown
Interface        Status    Reason
---------------  --------  --------
Ethernet1        up        None
Ethernet5        up        None
Ethernet9        up        None
Ethernet13       up        None
Ethernet17       up        None
Ethernet21       up        None
Ethernet25       up        None
Ethernet29       up        None
Ethernet33       up        None
Ethernet37       up        None
Ethernet41       up        None
Ethernet45       up        None
Ethernet49       up        None
Ethernet53       up        None
Ethernet57       up        None
Ethernet61       up        None
Ethernet65       up        None
Ethernet69       up        None
Ethernet73       up        None
Ethernet77       up        None
Ethernet81       up        None
Ethernet85       up        None
Ethernet89       up        None
Ethernet93       up        None
Ethernet97       up        None
Ethernet101      up        None
Ethernet105      up        None
Ethernet109      up        None
Ethernet113      up        None
Ethernet117      errdown   Link flap
Ethernet121      up        None
Ethernet125      up        None
Ethernet129      up        None
Ethernet130      up        None

clear counters interface

[Command]
clear counters interface

[Purpose]
Clear interface count

[View]
System view

[Use Cases]

sonic# clear counters interface
Cleared counters

interface ethernet

[Command]
interface ethernet interface_id

[Purpose]
Switch to ethernet view

[Parameter]

Parameter	Description
interface_id	Interface id

[View]
System configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# interface ethernet 1
sonic(config-if-1)# show this
!
interface ethernet 1

shutdown

[Command]
shutdown no shutdown

[Purpose]
Shutdown interface

[View]
Interface view

[Usage Scenario]
When you have made changes to the interface’s operational parameters, and the new configuration does not take effect immediately, you can use the “shutdown” and “undo shutdown” commands to disable and re-enable the interface to apply the new configuration. Also, when an interface is idle, it is advisable to use the “shutdown” command to deactivate that interface. This helps prevent any issues that may arise due to interference on the interface when it’s not in use.

[Use Cases]

sonic# configure terminal
sonic(config)# interface ethernet 1
sonic(config-if-1)# shutdown
sonic(config-if-1)# show this
!
interface ethernet 1
shutdown

link-flapping detect enable

[Command]
link-flapping detect enable

no link-flapping detect enable

[Purpose]
Enable/disable the link-flapping feature on the interface.

[View]
Interface view

[Use Cases]

sonic# configure terminal
sonic(config)# interface ethernet 121
sonic(config-if-121)# link-flapping detect enable
sonic(config-if-121)#

link-flapping detect-action error-down

[Command]
link-flapping detect-action error-down

no link-flapping detect-action error-down

[Purpose]
Configure/Remove the interface status after the link-flapping threshold is triggered.

[View]
Interface view

[Usage Scenario]
When the device interface frequently alternates between UP and DOWN states, it will proactively enter the errdisable state.

[Notes]

Once an interface enters the errdisable state, it cannot recover automatically; manual restoration by executing the shutdown/no shutdown command in the interface view is required.

[Use Cases]

sonic# configure terminal
sonic(config)# interface ethernet 121
sonic(config-if-121)# link-flapping detect-action error-down

link-flapping detect-interval

[Command]
link-flapping detect-interval time

no link-flapping detect-interval

[Purpose]
Configure/Remove the link-flapping monitoring period.

[Parameter]

Parameter	Description
time	Interface UP/DOWN monitoring period; Unit: seconds; Range: 5-60.

[View]
Interface view

[Use Cases]

sonic# configure terminal
sonic(config)# interface ethernet 121
sonic(config-if-121)# link-flapping detect-interval 30

link-flapping detect-threshold

[Command]
link-flapping detect-threshold threshold_num

no link-flapping detect-threshold

[Purpose]
Configure/Remove the threshold for frequent interface UP/DOWN events.

[Parameter]

Parameter	Description
threshold_num	Interface UP/DOWN count; Range: 5-30.

[View]
Interface view

[Use Cases]

sonic# configure terminal
sonic(config)# interface ethernet 121
sonic(config-if-121)# link-flapping detect-interval 30

speed

[Command]
speed speed

[Purpose]
Configure the interface rate

[Parameter]

Parameter	Description
speed	Rate in Mbit. Selectable 10/100/1000/2500/10000/25000/40000/100000/auto.

[View]
Interface view

[Use Cases]

sonic# configure terminal
sonic(config)# interface ethernet 1
sonic(config-if-1)# speed 10000
sonic(config-if-1)# show this
!
interface ethernet 1
 speed 10000

limit-rate {ingress|egress} bind

[Command]
limit-rate {ingress|egress} bind cir cbr

no limit-rate {ingress|egress} bind

[Purpose]
Configure interface rate limiting function

[Parameter]

Parameter	Description
cir	Specifes the committed information rate (CIR), which is the allowed rate at which trafc can pass through. (unit: KBytes)
cbr	Specifes the committed burst size (CBS), which is the average volume of burst trafc that can pass through an interface. (unit: Bytes)

[View]
Interface view

[Use Cases]

sonic# configure terminal
sonic(config)# interface ethernet 1
sonic(config-if-1)# limit-rate ingress bind 1000 100
sonic(config-if-1)# limit-rate egress bind 200 200
sonic(config-if-1)# show this
!
interface ethernet 1
limit-rate egress bind 200 200
limit-rate ingress bind 1000 100

mtu

[Command]
mtu mtu

[Purpose]
Configure interface MTU

[Parameter]

Parameter	Description
mtu	Maximum Transmission Unit, Scope: 1312～9216

[View]
Interface view

[Use Cases]

sonic# configure terminal
sonic(config)# interface ethernet 1
sonic(config-if-1)# mtu 2000
sonic(config-if-1)# show this
!
interface ethernet 1
 mtu 2000

startup-delay

[Command]
startup-delay time

no startup-delay

[Purpose]
Configure interface delayed start time

[Parameter]

Parameter	Description
time	Value range: 1-300, unit: s

[View]
Interface view

[Usage Scenario]
In unstable network environments, there may be situations where the device cannot obtain an IP address from the expected DHCP server. If the device acquires an IP address from another DHCP server, even after network recovery, it may remain unable to obtain an IP address from the desired subnet for an extended period. To avoid this scenario, users can specify a delay in port activation time for the device after a reboot, depending on the network conditions.

[Notes]
When the time parameter is configured to 0, it means no delayed start is enabled.

[Use Cases]

sonic(config)# interface ethernet 1
sonic(config-if-1)# startup-delay 100

description

[Command]
description description
no description

[Purpose]
Configure interface description information

[Parameter]

Parameter	Description
description	Interface description

[View]
Interface view

[Notes]
Only one description for an interface, which will be overwritten by multiple configurations.

[Use Cases]

sonic# configure terminal
sonic(config)# interface ethernet 1
sonic(config-if-1)# description abc
sonic(config-if-1)# show this
!
interface ethernet 1
 description abc

breakout

[Command]
breakout {4x25G|4x10G|4x1G}
no breakout

[Purpose]
Configure static splitting for the interface

[Parameter]

Parameter	Description
4x25G	Split the 100G interface into 4x25G
4x10G	Split the 100G interface into 4x10G
4x1G	Split the 100G interface into 4x1G

[View]
Interface view

[Notes]
When splitting, do not check configuration dependencies; however, check the configuration dependencies for sub-interfaces 1-4 during merging. After splitting, a device restart is required for the changes to take effect

[Use Cases]

sonic(config)# interface ethernet 49
sonic(config-if-49)# breakout 4x25G

speed auto

[Command]
speed auto

[Purpose]
Enable interface speed adaptation

[View]
Interface view

[Usage Scenario]
The device defaults to enabling interface speed auto-negotiation. After manually modifying the interface speed, this command can be used to restore the interface speed auto-negotiation feature.

[Use Cases]

sonic(config)# interface ethernet 1
sonic(config-if-1)# speed auto

Sub-interface Configuration

show sub-interface

[Command]
show sub-interface {ethernet interface_name.subinterface_number | status}

[Purpose]
Display sub-interface status information

[Parameter]

Parameter	Description
interface_name	Parent interface name
subinterface_number	Sub-interface ID

[View]
System view

[Use Cases]

sonic# show sub-interface status
+----------------------+-------+--------+---------+---------------------+
| Sub port interface   | MTU   | vlan   | Admin   | Type                |
+======================+=======+========+=========+=====================+
| Eth1.3000            | 9216  | 3000   | up      | dot1q-encapsulation |
+----------------------+-------+--------+---------+---------------------+
| Eth40.3000           | 9216  | 3000   | up      | dot1q-encapsulation |
+----------------------+-------+--------+---------+---------------------+

interface sub-ethernet

[Command]
interface sub-ethernet interface_name.subinterface_number
no interface sub-ethernet interface_name.subinterface_number

[Purpose]
Add sub-interface

[Parameter]

Parameter	Description
interface_name	Parent interface name
subinterface_number	Sub-interface ID

[View]
System configuration view

[Notes]
If the sub-interface is configured with an IP address, the IP address of the sub-interface must be deleted before the sub-interface can be deleted.

[Use Cases]

sonic# configure terminal
sonic(config)# interface sub-ethernet 40.1000
sonic(config-if-40.1000)#

Loopback Interface Configuration

interface loopback

[Command]
interface loopback loopback_id

[Purpose]
Switch to loopback view

[Parameter]

Parameter	Description
loopback_id	Loopback port ID

[View]
System configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# interface loopback 0
sonic(config-loif-0)# show this
!
interface loopback 0

ip address

[Command]
ip address A.B.C.D/M

[Purpose]
Adding an IP address to the loopback port

[Parameter]

Parameter	Description
A.B.C.D/M	IP address with prefix length

[View]
System configuration view

[Notes]
The IPv4 address configured on the Loopback port is not allowed to be deleted and can be overwritten by reconfiguration.

[Use Cases]

sonic# configure terminal
sonic(config)# interface loopback 2
sonic(config-loif-2)# ip address 3.3.3.6/24
sonic(config-loif-2)# show this
!
interface loopback 2
ip address 3.3.3.6/24

Port Group Configuration

port-group ethernet

[Command]
port-group ethernet interface_range

[Purpose]
Create port group

[View]
System configuration view

[Usage Scenario]
Creating an interface group is designed to facilitate the identical configuration of multiple Ethernet interfaces. Configuring each interface individually can easily lead to errors and result in a significant amount of repetitive work. By establishing an interface group, it becomes possible to centrally manage the configuration of these interfaces, thereby enhancing efficiency and reducing the likelihood of configuration errors.

[Use Cases]

sonic(config)# port-group ethernet 1-20
sonic(config-port-group-1-20)# switchport vlan access 10

port-group lag

[Command]
port-group lag lag_range

[Purpose]
Create lag group

[View]
System configuration view

[Usage Scenario]
Creating a lag group is designed to facilitate the identical configuration of multiple lags. Configuring each lag individually can easily lead to errors and result in a significant amount of repetitive work. By establishing an lag group, it becomes possible to centrally manage the configuration of these lags, thereby enhancing efficiency and reducing the likelihood of configuration errors.

[Use Cases]

sonic(config)# port-group lag 1-20
sonic(config-lag-group-1-20)# switchport vlan access 10