For 8800 phones on Cisco Unified CM, Cisco recommends DHCP custom option 150 with the TFTP server IP address as its value, and suggests DHCP option 66 if option 150 cannot be used.
Checked 2026-10-02
If you cannot use option 150, you may try using DHCP option 66.
- Vendor
- Cisco
- Product
- Cisco IP Phone 8800 Series
- Subsystem
- TFTP discovery
- Deployment
- on-premises
- Region
- not restricted
- Release range
- current as of 2026-10-02
- Checked
- 2026-10-02
Sources
- Cisco IP Phone 8800 Series Administration Guide for Cisco Unified Communications Manager - Technical Details — Cisco Systems · tier 2 current vendor documentation · Network Protocols table > DHCP row
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-option-150-recommended. WarmTransfer. https://warmtransfer.net/knowledge/claims/ip-phone-dhcp-vlan-troubleshooting-option-150-recommended
BibTeX
@misc{warmtransfer-claim-ip-phone-dhcp-vlan-troubleshooting-option-150-recommended,
title = {Troubleshooting IP phones that do not get a voice VLAN or DHCP options: source note ip-phone-dhcp-vlan-troubleshooting-option-150-recommended},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/ip-phone-dhcp-vlan-troubleshooting-option-150-recommended},
note = {Source note ip-phone-dhcp-vlan-troubleshooting-option-150-recommended, checked 2026-10-02}
}