Inference: on a Catalyst 9300 left at documented defaults, a non-Cisco phone that learns its VLAN only through LLDP-MED will not get a voice VLAN until LLDP is enabled globally (lldp run), because CDP is on by default and LLDP is off.

inferred · Checked 2026-09-24

Vendor
Cisco
Product
Catalyst 9300 Series Switches
Subsystem
LLDP-MED / voice VLAN
Deployment
on-premises
Region
not restricted
Release range
IOS XE 17.15.x to 17.17.x
Status
inferred
Checked
2026-09-24

Sources

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-infer-c9300-lldp-for-3p-phones. WarmTransfer. https://warmtransfer.net/knowledge/claims/voice-vlan-lldp-poe-infer-c9300-lldp-for-3p-phones

BibTeX

@misc{warmtransfer-claim-voice-vlan-lldp-poe-infer-c9300-lldp-for-3p-phones,
  title  = {Voice VLAN and LLDP-MED and CDP and PoE for IP phones: source note voice-vlan-lldp-poe-infer-c9300-lldp-for-3p-phones},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/voice-vlan-lldp-poe-infer-c9300-lldp-for-3p-phones},
  note   = {Source note voice-vlan-lldp-poe-infer-c9300-lldp-for-3p-phones, checked 2026-09-24}
}

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