DHCP Relay Follow

Reference model:

• Switch model name:

- AS7726-32X

- AS7326-56X

- AS7816-64X

- AS5835-54X(T)

- AS4630-54PE

- AS9716-32D

- AS8000(Minipack)

- Wedge100BF-32X

• Edgecore SONiC version: 

- Edgecore-SONiC_20201123_130028_ec202006_74

- Edgecore-SONiC_20201229_070315_ec202006_101

- Edgecore-SONiC_20201229_070315_ec202006_bfn_65(Wedge100BF-32X)

Topology :

DHCP server belongs to VLAN 10 and connects to the switch Ethernet4.

DHCP client belongs to VLAN 20 and connects to the switch Ethernet2.

Procedure :

Step 1. Configure VLAN and IP address properly (Refer to this article)

Create VLAN10 with member Ethernet4 and binding the IP to VLAN10. 

admin@sonic:~$ sudo config vlan add 10    
admin@sonic:~$ sudo config vlan member add -u 10 Ethernet4     
admin@sonic:~$ sudo config interface ip add Vlan10 192.168.10.10/24

Create VLAN20 with member Ethernet2 and binding the IP to VLAN20. 

admin@sonic:~$ sudo config vlan add 20    
admin@sonic:~$ sudo config vlan member add -u 20 Ethernet2    
admin@sonic:~$ sudo config interface ip add Vlan20 192.168.20.10/24

Step 2. Save above setting to config_db.json

admin@sonic:~$ sudo config save -y

Step 2. Add DHCP relay server IP address to VLAN 20

admin@sonic:~$ sudo config vlan dhcp_relay add 20 192.168.10.2   

Step 3. Save above setting to config_db.json

admin@sonic:~$ sudo config save -y

Step 4. Check the setting information by SONiC command.

admin@sonic:~$ show vlan brief         
+-----------+------------------+-----------+----------------+-----------------------+
|   VLAN ID | IP Address       | Ports     | Port Tagging   | DHCP Helper Address   |
+===========+==================+===========+================+=======================+
|        10 | 192.168.10.10/24 | Ethernet4 | untagged       |                       |
+-----------+------------------+-----------+----------------+-----------------------+
|        20 | 192.168.20.10/24 | Ethernet2 | untagged       | 192.168.10.2          |
+-----------+------------------+-----------+----------------+-----------------------+