DHCP relay on SG350

[snowflocke]

Hey I have an issue with the dhcp relay on my sg350. To break it down I have two VLANs on the Switch,those are connected through a Opnsense Firewall. Traffic von VLAN50 to VLAN30 is unrestricted, the DHCP Server is on VLAN30. I made a Scope for the VLAN50 Network and configured the relay agent, but it didnt work (Also tried it on the Firewall without success). Im a bit out of ideas right now, so maybe someone here could help.

I made some Screenshots for better understanding:

https://imgur.com/a/NCxgWio

[balaji.bandi]

suggest to try this :

https://www.cisco.com/c/en/us/support/docs/smb/switches/cisco-350-series-managed-switches/smb5406-configure-dynamic-host-configuration-protocol-dhcp-snooping.html

[snowflocke]

I followed that guide but couldnt make it work

https://imgur.com/a/qIK1lDH

[balaji.bandi]

You can Login to SSH and can you post-show run from the device :

(config)#int vlan 50

(config-if)#ip helper-address 192.168.30.11

[snowflocke]

that looks like an ios statement for me. this is the relevant config, Vlan 30 an 50 are seperated by an opnsense, with trafic from vlan 50 to 30 unrestricted.

ip dhcp relay address 192.168.30.11
ip dhcp relay enable
interface vlan 20
name DMZ
ip dhcp relay enable

interface vlan 30
name SERVER
ip address 192.168.30.5 255.255.255.0
ip dhcp relay enable

interface vlan 50
name LAN
ip address 192.168.50.5 255.255.255.0
ip dhcp relay enable

interface Port-Channel1
flowcontrol on
loopback-detection enable
description ESXI
no snmp trap link-status
ip dhcp snooping trust
switchport mode trunk
switchport trunk native vlan none
switchport trunk allowed vlan remove 1-9,11-19,21-29,31-49,51-4094

ip dhcp snooping
ip dhcp snooping database
ip dhcp snooping information option allowed-untrusted

[balaji.bandi]

I am more interested to know more information -"Vlan 30 an 50 are separated by an opnsense"

1. is the SG350 setup as Layer3 mode - by default, it wil be Layer 2 only

2. where is the DHCP Server is this in the SG350 or outside?

3. do you have reachability from that VLAN you trying to get DHCP Address?

[snowflocke]

I dont have IPv4 Routing activated on the switch. The sg 350 soesnt have a layer 2/3 switch like the predeccessor. Both vlans have a IP interface. When Im in vlan 50 and give myself a static address I can reach the dhcp router.