How to configure Sub Interface
Sub interfaces divide the parent interface into two or more virtual interfaces on which you can assign unique Layer 3 parameters such as IP addresses and dynamic routing protocols. The IP address for each sub interface should be in a different subnet from any other sub interface on the parent interface.
Tested model & firmware version:
Switch model name:
Accton-AS5712-54X
Community sonic version:
202211.2
NOTE:
There is no L2 bridging across these subport interfaces; each subport interface is regarded to be in its own bridge domain.
The MTU of the sub-interface will not be configured; instead, it will inherit the value of the parent interface.
Parent interface is not a router port and should be a physical port or a port-channel.
The VLAN cannot be utilised for a standard VLAN if the sub-interface is using it.
SUB INTERFACE WITH IP:
TOPOLOGY:
\
Note: Commands are to be executed in sudo mode.
Configure an IP address for sub interfaces as per topology.
Router1:
root@sonic:/home/admin# config interface ip add Ethernet48.1 10.1.1.1/24
Router2:
root@sonic:/home/admin# config interface ip add Ethernet48.1 10.1.1.2/24
VALIDATION (SONIC SHOW OUTPUTS)
Subinterfaces and IP information.
Router1:
root@sonic:/home/admin# show subinterfaces status
Sub port interface Speed MTU Vlan Admin Type
-------------------- ------- ----- ------ ------- --------------------
Ethernet48.1 10G 9100 1 up 802.1q-encapsulation
root@sonic:/home/admin# show ip interfaces
Interface Master IPv4 address/mask Admin/Oper BGP Neighbor Neighbor IP
----------- -------- ------------------- ------------ -------------- -------------
Ethernet48.1 10.1.1.1/24 up/up N/A N/A
Loopback1 2.2.2.2/32 up/up N/A N/A
docker0 240.127.1.1/24 up/down N/A N/A
eth0 172.26.1.81/24 up/up N/A N/A
lo 127.0.0.1/16 up/up N/A N/A
Router2:
root@sonic:/home/admin# show subinterfaces status
Sub port interface Speed MTU Vlan Admin Type
-------------------- ------- ----- ------ ------- --------------------
Ethernet48.1 10G 9100 1 up 802.1q-encapsulation
root@sonic:/home/admin# show ip interfaces
Interface Master IPv4 address/mask Admin/Oper BGP Neighbor Neighbor IP
----------- -------- ------------------- ------------ -------------- -------------
Ethernet48.1 10.1.1.2/24 up/up N/A N/A
Loopback1 2.2.2.2/32 up/up N/A N/A
docker0 240.127.1.1/24 up/down N/A N/A
eth0 172.26.1.82/24 up/up N/A N/A
lo 127.0.0.1/16 up/up N/A N/A
Ping Router1(Ethernet48.1) to Router2(Ethernet48.1).
root@sonic:/home/admin# ping 10.1.1.2
PING 10.1.1.2 (10.1.1.2) 56(84) bytes of data.
64 bytes from 10.1.1.2: icmp_seq=1 ttl=64 time=0.480 ms
--- 10.1.1.2 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.480/0.480/0.480/0.000 ms
root@sonic:/home/admin# show arp
Address MacAddress Iface Vlan
------------ ----------------- ------------ ------
10.1.1.2 04:f8:f8:81:da:8c Ethernet48.1 -
SUB INTERFACE WITH IP and VLAN:
TOPOLOGY:
Configuration commands (sonic configurations):
Note: Commands are to be executed in sudo mode.
Router1: Configure an IP address for sub interfaces as per topology.
root@sonic:/home/admin# config interface ip add Ethernet48.1 10.1.1.1/24
Router2: Add the Ethernet ports in a VLAN and configure an IP address for VLAN.
VALIDATION (SONIC SHOW OUTPUTS)
Subinterfaces , IP and vlan information.
Router1:
root@sonic:/home/admin# show subinterfaces status
Sub port interface Speed MTU Vlan Admin Type
-------------------- ------- ----- ------ ------- --------------------
Ethernet48.10 10G 9100 10 up 802.1q-encapsulation
root@sonic:/home/admin# show ip interfaces
Interface Master IPv4 address/mask Admin/Oper BGP Neighbor Neighbor IP
----------- -------- ------------------- ------------ -------------- -------------
Ethernet48.10 10.1.1.1/24 up/up N/A N/A
Loopback1 2.2.2.2/32 up/up N/A N/A
docker0 240.127.1.1/24 up/down N/A N/A
eth0 172.26.1.81/24 up/up N/A N/A
lo 127.0.0.1/16 up/up N/A N/A
Router2:
root@sonic:/home/admin# show ip interfaces
Interface Master IPv4 address/mask Admin/Oper BGP Neighbor Neighbor IP
----------- -------- ------------------- ------------ -------------- -------------
Vlan10 10.1.1.2/24 up/up N/A N/A
Loopback1 2.2.2.2/32 up/up N/A N/A
docker0 240.127.1.1/24 up/down N/A N/A
eth0 172.26.1.82/24 up/up N/A N/A
lo 127.0.0.1/16 up/up N/A N/A
root@sonic:/home/admin# show vlan brief
+-----------+-----------------+---------------+----------------+-----------------------+
| VLAN ID | IP Address | Ports | Port Tagging | DHCP Helper Address |
+===========+=================+===============+================+=======================+
| 10 | 10.1.1.2/24 | Ethernet48 | tagged | |
+-----------+-----------------+---------------+----------------+-----------------------+
Ping Router1(Ethernet48.10) to Router2(Vlan10).
root@sonic:/home/admin# ping 10.1.1.2
PING 10.1.1.2 (20.1.1.2) 56(84) bytes of data.
64 bytes from 10.1.1.2: icmp_seq=1 ttl=64 time=0.320 ms
--- 10.1.1.2 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.320/0.320/0.320/0.000 ms
Router1 :
root@sonic:/home/admin# show arp
Address MacAddress Iface Vlan
------------ ----------------- ------------- ------
10.1.1.2 04:f8:f8:81:da:8c Ethernet48.10 -
Router2:
root@sonic:/home/admin# show arp
Address MacAddress Iface Vlan
------------ ----------------- ------------ ------
10.1.1.1 68:21:5f:9c:fc:7b Ethernet48 10
SUB INTERFACE WITH PORTCHANNEL:
TOPOLOGY:
Configuration commands (sonic configurations):
Note: Commands are to be executed in sudo mode.
Router1:
Configure a Portchannel and add the Ethernet Ports in Portchannel.
Add the portchannel in a VLAN and assign the IP address.
Configure IP for subinterface in a portchannel.
root@sonic:/home/admin# config interface ip add PortChannel1.20 20.1.1.1/24
Router2:
Configure a Portchannel and add the Ethernet Ports in Portchannel.
Add the portchannel in a VLAN and assign the IP address.
VALIDATION (SONIC SHOW OUTPUTS)
Subinterfaces information.
Router1:
root@sonic:/home/admin# show subinterfaces status
Sub port interface Speed MTU Vlan Admin Type
-------------------- ------- ----- ------ ------- --------------------
PortChannel1.20 10G 9100 20 up 802.1q-encapsulation
root@sonic:/home/admin# show ip interfaces
Interface Master IPv4 address/mask Admin/Oper BGP Neighbor Neighbor IP
----------- -------- ------------------- ------------ -------------- -------------
PortChannel1.20 20.1.1.1/24 up/up N/A N/A
Loopback1 2.2.2.2/32 up/up N/A N/A
docker0 240.127.1.1/24 up/down N/A N/A
eth0 172.26.1.82/24 up/up N/A N/A
lo 127.0.0.1/16 up/up N/A N/A
root@sonic:/home/admin# show vlan brief
+-----------+-----------------+---------------+----------------+-----------------------+
| VLAN ID | IP Address | Ports | Port Tagging | DHCP Helper Address |
+===========+=================+===============+================+=======================+ | 10 | 10.1.1.1/24 | PortChannel1 | tagged | |
+-----------+-----------------+---------------+----------------+-----------------------+
Router2:
root@sonic:/home/admin# show ip interfaces
Interface Master IPv4 address/mask Admin/Oper BGP Neighbor Neighbor IP
----------- -------- ------------------- ------------ -------------- -------------
Vlan10 10.1.1.2/24 up/up N/A N/A
Vlan20 20.1.1.2/24 up/up N/A N/A
docker0 240.127.1.1/24 up/down N/A N/A
eth0 172.26.1.83/24 up/up N/A N/A
lo 127.0.0.1/16 up/up N/A N/A
root@sonic:/home/admin# show vlan brief
+-----------+-----------------+---------------+----------------+-----------------------+
| VLAN ID | IP Address | Ports | Port Tagging | DHCP Helper Address |
+===========+=================+===============+================+=======================+
| 10 | 10.1.1.2/24 | PortChannel1 | tagged | |
+-----------+-----------------+---------------+----------------+-----------------------+
| 20 | 20.1.1.2/24 | PortChannel1 | tagged | |
+-----------+-----------------+---------------+----------------+-----------------------+
Ping Router1(Vlan10) to Router2(Vlan10).
Ping Router1(PortChannel1.20) to Router2(Vlan20).
root@sonic:/home/admin# ping 10.1.1.2
PING 10.1.1.2 (10.1.1.2) 56(84) bytes of data.
64 bytes from 10.1.1.2: icmp_seq=1 ttl=64 time=0.631 ms
--- 10.1.1.2 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.631/0.631/0.631/0.000 ms
root@sonic:/home/admin# ping 20.1.1.2
PING 20.1.1.2 (20.1.1.2) 56(84) bytes of data.
64 bytes from 20.1.1.2: icmp_seq=1 ttl=64 time=0.516 ms
--- 20.1.1.2 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.516/0.516/0.516/0.000 ms
Router1:
root@sonic:/home/admin# show arp
Address MacAddress Iface Vlan
------------ ----------------- --------------- ------
10.1.1.2 68:21:5f:9c:fc:7b PortChannel1 10
20.1.1.2 68:21:5f:9c:fc:7b PortChannel1.20 -
Router2:
root@sonic:/home/admin# show arp
Address MacAddress Iface Vlan
------------ ----------------- ------------- ------
10.1.1.1 04:f8:f8:81:da:8c PortChannel1 10
20.1.1.1 04:f8:f8:81:da:8c PortChannel1 20
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