cisco business 350 switch - dhcp requests

[ReadersUK]

Hi

I have a simple setup that works with standard catalyst switches but on the 350 it doesn't. I have an access port connected to a firewall for guest on vlan 501, the firewall acts as dhcp server. The vlan is unrouted so no interface vlan 501 on switch, on a catalyst a client on vlan 501 sending a dhcp request to the firewall gets a dhcp address, on the 350 it doesn't work so wondering if there's some config I'm missing. My relevant 350 config is below:

vlan database
vlan 101,201,501

interface GigabitEthernet5
description Connected-to-Primary-FW-Port-Guest
switchport access vlan 501
no macro auto smartport

Thats it, the firewall is a dhcp server in this case. Any help welcome.

Regards

[balaji.bandi]

So the Gateway and DHCP confgured on the Firewall -

what device you using to get DHCP, what port on the switch its connected, what is the configuration on that Port- that port should also belong to VLAN 501 to get DHCP (by default all ports are on VLAN 1)

so make sure device connected port belong to VLAN 501.

Also you can configure manually PC same subnet as 501 IP address and see are you able to ping FW gateway ?

[M02@rt37]

Hello @ReadersUK 

You Catalyst was a C29XX ? A traditionnal L2 Switch ?

CBS350 act as L3 Sw I think in your case and you need to relay the DHCP requestion to your Firewall.

Add SVI 501 on CBS 350 and add on it this command:

ip dhcp relay enable

  Under config-terminal add this command also:

ip dhcp relay address x.x.x.x

With x.x.x.x IP on your Fw. 

https://www.cisco.com/c/en/us/td/docs/switches/lan/csbms/CBS_250_350/CLI/cbs-350-cli-/dhcp-relay-commands.html

[ReadersUK]

Hi

Thanks for your reply, however we don't want to route the guest network so never use a SVI. The config works on all our switches, mostly 3850's and 9300's, as a dhcp request on a vlan is just broadcast and our firewall responds but not on the business350 it seems.

[M02@rt37]

Ok @ReadersUK 

Thanks for that clarification!

On your Firewall, do you see the DCHP Demand from the client ?

[ReadersUK]

Hi
To be sure I configured a normal svi and dhcp pool on the switch and the client requests and gets dhcp ok. I did try your suggestion with svi and relay but that didn't work.

[balaji.bandi]

what device you using to get DHCP, what port on the switch its connected, what is the configuration on that Port- that port should also belong to VLAN 501 to get DHCP (by default all ports are on VLAN 1)