Source note · Voice VLAN and LLDP-MED and CDP and PoE for IP phones
After a Catalyst 9300 powers a port from the IEEE class, it uses CDP to learn the Cisco powered device's actual power need and adjusts the power budget to match.
Checked 2026-09-24
- Vendor
- Cisco
- Product
- Catalyst 9300 Series Switches
- Subsystem
- PoE negotiation
- Deployment
- on-premises
- Region
- not restricted
- Release range
- IOS XE 17.18.x
- Checked
- 2026-09-24
Sources
- Interface and Hardware Components Configuration Guide, Cisco IOS XE 17.18.x (Catalyst 9300 Switches) - Configuring Power over Ethernet — Cisco Systems · tier 2 current vendor documentation · Configuring Power over Ethernet > Powered-Device Detection and Initial Power Allocation
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-poe-cdp-adjusts. WarmTransfer. https://warmtransfer.net/knowledge/claims/voice-vlan-lldp-poe-c9300-poe-cdp-adjusts
BibTeX
@misc{warmtransfer-claim-voice-vlan-lldp-poe-c9300-poe-cdp-adjusts,
title = {Voice VLAN and LLDP-MED and CDP and PoE for IP phones: source note voice-vlan-lldp-poe-c9300-poe-cdp-adjusts},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/voice-vlan-lldp-poe-c9300-poe-cdp-adjusts},
note = {Source note voice-vlan-lldp-poe-c9300-poe-cdp-adjusts, checked 2026-09-24}
}