On Catalyst 9300, if an LLDP-MED network-policy profile is configured on an interface first, 'switchport voice vlan' cannot be applied to that interface afterwards. If the voice VLAN is configured first, a network-policy profile can still be added.

Checked 2026-10-02

If you first configure a network-policy profile on an interface, you cannot apply the switchport voice vlan command on the interface.
Vendor
Cisco
Product
Cisco Catalyst 9300 Series Switches
Subsystem
LLDP-MED
Deployment
on-premises
Region
not restricted
Release range
IOS XE 17.7.x
Checked
2026-10-02

Sources

Cite this note

APA

WarmTransfer. (2026, October 2). Troubleshooting IP phones that do not get a voice VLAN or DHCP options: source note ip-phone-dhcp-vlan-troubleshooting-netpolicy-blocks-vvlan. WarmTransfer. https://warmtransfer.net/knowledge/claims/ip-phone-dhcp-vlan-troubleshooting-netpolicy-blocks-vvlan

BibTeX

@misc{warmtransfer-claim-ip-phone-dhcp-vlan-troubleshooting-netpolicy-blocks-vvlan,
  title  = {Troubleshooting IP phones that do not get a voice VLAN or DHCP options: source note ip-phone-dhcp-vlan-troubleshooting-netpolicy-blocks-vvlan},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/ip-phone-dhcp-vlan-troubleshooting-netpolicy-blocks-vvlan},
  note   = {Source note ip-phone-dhcp-vlan-troubleshooting-netpolicy-blocks-vvlan, checked 2026-10-02}
}

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