Source note · Voice VLAN and LLDP-MED and CDP and PoE for IP phones
On Catalyst 9300, switchport priority extend trust tells the phone's access (PC) port to trust the priority received from the attached PC, and switchport priority extend cos <0-7> makes the phone override it, with a default of cos 0.
Checked 2026-09-24
The default priority is cos 0.
- Vendor
- Cisco
- Product
- Catalyst 9300 Series Switches
- Subsystem
- voice VLAN / PC port 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 > Configuring the Priority of Incoming Data Frames
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-extend-trust. WarmTransfer. https://warmtransfer.net/knowledge/claims/voice-vlan-lldp-poe-c9300-extend-trust
BibTeX
@misc{warmtransfer-claim-voice-vlan-lldp-poe-c9300-extend-trust,
title = {Voice VLAN and LLDP-MED and CDP and PoE for IP phones: source note voice-vlan-lldp-poe-c9300-extend-trust},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/voice-vlan-lldp-poe-c9300-extend-trust},
note = {Source note voice-vlan-lldp-poe-c9300-extend-trust, checked 2026-09-24}
}