For Catalyst 9300 voice VLAN to configure a Cisco IP phone, CDP must be enabled on the switch port the phone connects to. CDP is enabled globally by default.
Checked 2026-10-02
- Vendor
- Cisco
- Product
- Cisco Catalyst 9300 Series Switches
- Subsystem
- voice VLAN
- Deployment
- on-premises
- Region
- not restricted
- Release range
- IOS XE 17.18.x
- Checked
- 2026-10-02
Sources
- VLAN Configuration Guide, Cisco IOS XE 17.18.x (Catalyst 9300 Switches) - Configuring Voice VLANs — Cisco Systems · tier 2 current vendor documentation · Prerequisites for Voice VLANs
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting IP phones that do not get a voice VLAN or DHCP options: source note ip-phone-dhcp-vlan-troubleshooting-vvlan-needs-cdp. WarmTransfer. https://warmtransfer.net/knowledge/claims/ip-phone-dhcp-vlan-troubleshooting-vvlan-needs-cdp
BibTeX
@misc{warmtransfer-claim-ip-phone-dhcp-vlan-troubleshooting-vvlan-needs-cdp,
title = {Troubleshooting IP phones that do not get a voice VLAN or DHCP options: source note ip-phone-dhcp-vlan-troubleshooting-vvlan-needs-cdp},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/ip-phone-dhcp-vlan-troubleshooting-vvlan-needs-cdp},
note = {Source note ip-phone-dhcp-vlan-troubleshooting-vvlan-needs-cdp, checked 2026-10-02}
}