Cisco Support Community
Community Member

Cisco SF300-48P, DHCP relay issues for IP Phones

Hi People


I need some assistance for an issue where IP Phones receive an IP address from the incorrect scope, they continue to receive an address on the LAN scope, when they should be getting an IP from the VOIP scope.

The switch details are as follows

Firmware is latest

Layer 3 mode is enabled

VLAN 1 for Data is on Untagged

VLAN 100 for Voice is on tagged

vlan routing between these is fine.

I am able to ping both vlan interfaces from the Windows DHCP Server.

DHCP relay has been configured and the IP Helper has also been setup to point to the DHCP Server on

The port (fe2) the phone is currently into is set to trunk mode as the PC's will plug into the phones and the phones into the switch.

whatever i do the phones always seems to get an IP from the LAN scope on 10.132.74.x as opposed to the VOIP scope on 192.168.240.x, from what  i have read these switches have an auto voice vlan function (also setup) that auto senses and configures the correct VLAN ID based on preset macros.

i have attached a word document that contains a series screen shots from the GUI.

Normally on a Catalyst i would have used the cmds below, however these dont accepts these commands.

interface fe0/2
 description data and voip 
 switchport access vlan 1
 switchport mode access
 switchport voice vlan 100

Any pointers greatly appreciated.


Hi, these switches do not run

Hi, these switches do not run IOS so here is your CLI guide to help with correct commands:

What type of phones?  Do they show in LLDP or CDP neighbors as being tagged to VLAN 100?




-- please remember to rate and mark answered helpful posts --
CreatePlease to create content