Source note · Voice VLAN and LLDP-MED and CDP and PoE for IP phones
On Catalyst 9300 with port security on a voice VLAN port, the maximum secure addresses must be set to two plus the maximum allowed on the access VLAN, because the phone needs up to two MAC addresses.
Checked 2026-09-24
When the port is connected to a Cisco IP Phone, the phone requires up to two MAC addresses.
- Vendor
- Cisco
- Product
- Catalyst 9300 Series Switches
- Subsystem
- voice VLAN / port security
- 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 > Voice VLAN Configuration Guidelines
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-port-security-macs. WarmTransfer. https://warmtransfer.net/knowledge/claims/voice-vlan-lldp-poe-c9300-port-security-macs
BibTeX
@misc{warmtransfer-claim-voice-vlan-lldp-poe-c9300-port-security-macs,
title = {Voice VLAN and LLDP-MED and CDP and PoE for IP phones: source note voice-vlan-lldp-poe-c9300-port-security-macs},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/voice-vlan-lldp-poe-c9300-port-security-macs},
note = {Source note voice-vlan-lldp-poe-c9300-port-security-macs, checked 2026-09-24}
}