DELL Networking SONiC: How to Configure IPv4 Address and Maximum Transmission Unit in Layer 3 Interfaces

Summary: This article explains how to configure IPv4 address and maximum transmission unit (MTU) Interfaces in Dell Networking SONiC. This article uses a switch running Dell SONiC 4.1.

This article applies to This article does not apply to This article is not tied to any specific product. Not all product versions are identified in this article.

Instructions

 
Prerequisites
We are using standard interface naming to demonstrate the Concepts. See Dell article 202172 Dell Networking S-Series: Basic Interface Configuration - SONiC 4.0 for more information regarding interface naming


Index

Assign an IP address.

MTU
 

Assign an IP address.

Configuration Syntax
Command Explanation
admin@DELLSONiC:~$ sonic-cli
Enter Dell Management Command-Line Interface
DELLSONiC# configure terminal
Enter Configuration Mode
DELLSONiC(config)# interface <Eth slot/port><Vlan ID><PortChannel ID><Eth slot/port.subport><Loopback ID>
Configure Interface, VLAN, PortChannel, subinterface, Loopback.
DELLSONiC(conf-if-XXXX)# ip address A.B.C.D/mask
Configure IP address with mask.
DELLSONiC(conf-if-XXXX)# no ip address A.B.C.D/mask
Remove IP address.
DELLSONiC(conf-if-XXXX)# no shutdown
If the Interface is shut down, unshut the interface.

Show a command to verify the IP address.
Command Explanation
admin@DELLSONiC:~$ sonic-cli
Enter Dell Management Command-Line Interface
DELLSONiC# configure terminal
Enter Configuration Mode
DELLSONiC# show ip interfaces
Show IP configured in Interfaces.
DELLSONiC# show running-configuration interface <Eth slot/port><Vlan ID><PortChannel ID><Loopback ID> 
Show interface configuration
 
Let us configure an IP address on interface Eth 1/1 with IP address 10.0.0.1/24.
admin@DELLSONiC:~$ sonic-cli
DELLSONiC# configure
DELLSONiC(config)# interface Eth 1/1
DELLSONiC(config-if-Eth1/1)# ip address 10.0.0.1/24
DELLSONiC(config-if-Eth1/1)# end
DELLSONiC#

Let us verify the configuration.
DELLSONiC# show ip interfaces
Flags: U-Unnumbered interface, A-Anycast IP
-----------------------------------------------------------------------------------------------------------------
Interface            IP address/mask                              VRF                 Admin/Oper     Flags
-----------------------------------------------------------------------------------------------------------------
Eth1/1               10.0.0.1/24                                                      up/up
DELLSONiC# show running-configuration interface Eth 1/1
!
interface Eth1/1
 mtu 9100
 no shutdown
 ip address 10.0.0.1/24
DELLSONiC#

 

Let us configure IP address on VLAN 1 with IP address 10.0.0.1/24.
admin@DELLSONiC:~$ sonic-cli
DELLSONiC# configure
DELLSONiC(config)# interface Vlan 1
DELLSONiC(config-if-Vlan1)# ip address 10.0.0.1/24
DELLSONiC(config-if-Vlan1)# end
DELLSONiC#

Let us verify the configuration.
DELLSONiC# show ip interfaces
Flags: U-Unnumbered interface, A-Anycast IP
-----------------------------------------------------------------------------------------------------------------
Interface            IP address/mask                              VRF                 Admin/Oper     Flags
-----------------------------------------------------------------------------------------------------------------
Vlan1                10.0.0.1/24                                                      up/up
DELLSONiC# show running-configuration interface Vlan 1
!
interface Vlan1
 ip address 10.0.0.1/24
 
Let us configure IP address on PortChannel 1 with Ip address 10.0.0.1/24.
admin@DELLSONiC:~$ sonic-cli
DELLSONiC# configure
DELLSONiC(config)# interface PortChannel 1
DELLSONiC(config-if-po1)# ip address 10.0.0.1/24
DELLSONiC(config-if-po1)# end

Let us verify the configuration.
DELLSONiC# show ip interfaces
Flags: U-Unnumbered interface, A-Anycast IP
-----------------------------------------------------------------------------------------------------------------
Interface            IP address/mask                              VRF                 Admin/Oper     Flags
-----------------------------------------------------------------------------------------------------------------
PortChannel1         10.0.0.1/24                                                      up/up
DELLSONiC# show running-configuration interface PortChannel 1
!
interface PortChannel1
 no shutdown
 ip address 10.0.0.1/24
DELLSONiC#

 

Let us configure the IP address on Loopback 1 with IP address 10.0.0.1/32.
 
NOTE: Loopback supports /32 prefix length or subnet only.
 
 
admin@DELLSONiC:~$ sonic-cli
DELLSONiC# configure
DELLSONiC(config)# interface Loopback 1
DELLSONiC(config-if-lo1)# ip address 10.0.0.1/32
DELLSONiC(config-if-lo1)# end
DELLSONiC#

Let us verify the configuration.
DELLSONiC# show ip interfaces
Flags: U-Unnumbered interface, A-Anycast IP
-----------------------------------------------------------------------------------------------------------------
Interface            IP address/mask                              VRF                 Admin/Oper     Flags
-----------------------------------------------------------------------------------------------------------------
Loopback1            10.0.0.1/32                                                      up/up
DELLSONiC# show running-configuration interface Loopback 1
!
interface Loopback 1
 ip address 10.0.0.1/32
DELLSONiC#
 

Assign Anycast IP address

See Article Dell Networking SONiC How to configure Static Anycast gateway (anycast address) on how to configure anycast address. 

 

MTU

Configuration Syntax
Command Explanation
admin@DELLSONiC:~$ sonic-cli
Enter Dell Management Command-Line Interface
DELLSONiC# configure terminal
Enter Configuration Mode
DELLSONiC(config)# interface <Eth slot/port><Vlan ID><PortChannel ID><Eth slot/port.subport>
Configure Interface, VLAN, PortChannel, subinterface.
DELLSONiC(conf-if-XXXX)# mtu <MTU>
Configure MTU Change MTU (1312 to 9216). Default 9100
DELLSONiC(conf-if-XXXX)# no mtu
Configure the Default MTU in interface (Default is 9100).

Show commands to verify MTU.
Command Explanation
admin@DELLSONiC:~$ sonic-cli
Enter Dell Management Command-Line Interface
DELLSONiC# configure terminal
Enter Configuration Mode
DELLSONiC# show interface <Eth slot/port><Vlan ID><PortChannel ID>
Show Interface details.
DELLSONiC# show running-configuration interface <Eth slot/port><Vlan ID><PortChannel ID>
Show interface configuration
DELLSONiC#show interface status
Show interface status

 

  • MTU Configuration notes

    • Configure the MTU on VLAN members first before configuring VLAN MTU. All members of a VLAN must have the same MTU value. Tagged members must have a link MTU 4 bytes higher than untagged members to account for the packet tag.
    • Configure the MTU on port channel members first before you configure the port channel MTU. All members of a port channel must have the same MTU value. Tagged members must have a link MTU 4 bytes higher than untagged members to account for the packet tag.
    • Ensure that the MTU of port channel members is greater than or equal to the port channel MTU. If you configure the MTU on port channel members after you configure the port channel MTU, the port channel MTU may not be updated. The system selects the lowest MTU value that is configured on the port channel or port channel members to be the port channel MTU. For example, the port channel contains tagged members with Link MTU of 1522 and IP MTU of 1500 and untagged members with Link MTU of 1518 and IP MTU of 1500. The port channel’s Link MTU cannot be higher than 1518 bytes and its IP MTU cannot be higher than 1500 bytes.
Let us configure the MTU in interface Eth 1/1.
admin@DELLSONiC:~$ sonic-cli
DELLSONiC# configure
DELLSONiC(config)# interface Eth 1/1
DELLSONiC(config-if-Eth1/1)# mtu 1500
DELLSONiC(config-if-Eth1/1)# end

Let us verify the configuration (Output Grepped for brevity).
DELLSONiC# show interface status
--------------------------------------------------------------------------------------------------------------------------------------
Name                Description                   Oper           Reason         AutoNeg   Speed          MTU            Alternate Name
--------------------------------------------------------------------------------------------------------------------------------------
Eth1/1              -                             up             oper-up        off       25000          1500           Ethernet0
DELLSONiC# show running-configuration interface Eth 1/1
!
interface Eth1/1
 mtu 1500
 no shutdown
DELLSONiC# show interface Eth 1/1

Eth1/1 is up, line protocol is up, reason oper-up
Hardware is Eth, address is xx:xx:xx:xx:xx:xx
Mode of IPV4 address assignment: not-set
Mode of IPV6 address assignment: not-set
Interface IPv6 oper status: Disabled
IP MTU 1500 bytes
LineSpeed 25GB, Auto-negotiation off
Link-training: off

 

Let us configure MTU in VLAN interface.
admin@DELLSONiC:~$ sonic-cli
DELLSONiC# configure
DELLSONiC(config)# interface Vlan 1
DELLSONiC(config-if-Vlan1)# mtu 1500
DELLSONiC(config-if-Vlan1)# end
DELLSONiC#

Let us verify the configuration (Output Grepped for brevity).
DELLSONiC# show interface Vlan 1

Vlan1 is up, line protocol is up
Hardware is Vlan, address is xx:xx:xx:xx:xx:xx
Mode of IPV4 address assignment: not-set
Mode of IPV6 address assignment: not-set
Interface IPv6 oper status: Disabled
IP MTU 1500 bytes
Time since last interface status change: 02:33:17
DELLSONiC# show running-configuration interface Vlan 1
!
interface Vlan1
 mtu 1500

 

Let us configure PortChannel 1 with MTU 1500.
admin@DELLSONiC:~$ sonic-cli
DELLSONiC# configure
DELLSONiC(config)# interface PortChannel 1
DELLSONiC(config-if-po1)# mtu 1500
DELLSONiC(config-if-po1)# end
DELLSONiC#

Let us verify the configuration (Output Grepped for brevity).
DELLSONiC# show running-configuration interface PortChannel 1
!
interface PortChannel1 mode on
 mtu 1500
 no shutdown
DELLSONiC# show interface status
--------------------------------------------------------------------------------------------------------------------------------------
Name                Description                   Oper           Reason         AutoNeg   Speed          MTU            Alternate Name
--------------------------------------------------------------------------------------------------------------------------------------
Eth1/1              -                             up             oper-up        off       25000          1500           Ethernet0
Eth1/2              -                             up             oper-up        off       25000          1500           Ethernet1


PortChannel1        -                             up             oper-up        -         25000          1500           -
DELLSONiC# show interface PortChannel 1
PortChannel1 is up, line protocol is up, reason oper-up, mode Static
Hardware is PortChannel, address is xx:xx:xx:xx:xx:xx
Minimum number of links to bring PortChannel up is 1
Mode of IPV4 address assignment: not-set
Mode of IPV6 address assignment: not-set
Graceful shutdown: Disabled
MTU 1500
LineSpeed 25.0GB
Events:

Affected Products

Enterprise SONiC Distribution, PowerSwitch E3200-ON Series, Dell EMC Networking N3200-ON, PowerSwitch S5212F-ON, PowerSwitch S5224F-ON, PowerSwitch S5232F-ON, PowerSwitch S5248F-ON, PowerSwitch S5296F-ON, PowerSwitch Z9264F-ON, PowerSwitch Z9332F-ON , PowerSwitch Z9432F-ON ...
Article Properties
Article Number: 000218581
Article Type: How To
Last Modified: 10 Apr 2024
Version:  5
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