Source note · Voice VLAN and LLDP-MED and CDP and PoE for IP phones
The Catalyst 9300 (IOS XE 17.15.x) guide says to enable QoS with the trust device cisco-phone interface command before enabling voice VLAN, unless auto-QoS is used, which configures these settings automatically.
Checked 2026-09-24
Before you enable voice VLAN, enable QoS on the device by entering the trust device cisco-phone interface configuration command.
- Vendor
- Cisco
- Product
- Catalyst 9300 Series Switches
- Subsystem
- voice VLAN / QoS
- Deployment
- on-premises
- Region
- not restricted
- Release range
- IOS XE 17.15.x
- Checked
- 2026-09-24
Sources
- VLAN Configuration Guide, Cisco IOS XE 17.15.x (Catalyst 9300 Switches) - Configuring Voice VLANs — Cisco Systems · tier 2 current vendor documentation · Configuring Voice VLANs > Prerequisites for Voice VLANs
Cite this note
APA
WarmTransfer. (2026, September 24). Voice VLAN and LLDP-MED and CDP and PoE for IP phones: source note voice-vlan-lldp-poe-c9300-vv-trust-first. WarmTransfer. https://warmtransfer.net/knowledge/claims/voice-vlan-lldp-poe-c9300-vv-trust-first
BibTeX
@misc{warmtransfer-claim-voice-vlan-lldp-poe-c9300-vv-trust-first,
title = {Voice VLAN and LLDP-MED and CDP and PoE for IP phones: source note voice-vlan-lldp-poe-c9300-vv-trust-first},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/voice-vlan-lldp-poe-c9300-vv-trust-first},
note = {Source note voice-vlan-lldp-poe-c9300-vv-trust-first, checked 2026-09-24}
}