Because the MPP default DHCP Option To Use list places 66 before 150, an MPP phone in a scope that carries both options with different values is likely to act on option 66. That is the opposite of the RFC 5859 recommendation that option 150 take priority.
inferred · Checked 2026-10-02
- Vendor
- Cisco
- Product
- Cisco IP Phone Multiplatform Firmware
- Subsystem
- DHCP
- Deployment
- multi-tenant, on-premises
- Region
- not restricted
- Release range
- current as of 2026-10-02
- Status
- inferred
- Checked
- 2026-10-02
Sources
- Cisco IP Desk Phone with Multiplatform Firmware (MPP) - Administration Guide - Technical Details — Cisco Systems · tier 2 current vendor documentation · Network Protocols > DHCP (DHCP Option To Use default), read against rfc-5859-tftp-server-address-option Section 3
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-infer-mpp-66-before-150. WarmTransfer. https://warmtransfer.net/knowledge/claims/ip-phone-dhcp-vlan-troubleshooting-infer-mpp-66-before-150
BibTeX
@misc{warmtransfer-claim-ip-phone-dhcp-vlan-troubleshooting-infer-mpp-66-before-150,
title = {Troubleshooting IP phones that do not get a voice VLAN or DHCP options: source note ip-phone-dhcp-vlan-troubleshooting-infer-mpp-66-before-150},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/ip-phone-dhcp-vlan-troubleshooting-infer-mpp-66-before-150},
note = {Source note ip-phone-dhcp-vlan-troubleshooting-infer-mpp-66-before-150, checked 2026-10-02}
}