Source note · Setting up 802.1X authentication for Cisco IP phones
Cisco IP Phones can send a CDP message telling the switch that the PC port link is down, so the switch can clear the data device's session immediately.
Checked 2026-10-02
- Vendor
- Cisco
- Product
- Cisco TrustSec
- Subsystem
- 802.1X design
- Deployment
- on-premises
- Region
- not restricted
- Release range
- 2014 design guidance
- Checked
- 2026-10-02
Sources
- IP Telephony for 802.1X Design Guide — Cisco Systems · tier 2 current vendor documentation · Link State Problem > CDP Enhancement for Second Port Disconnect
Cite this note
APA
WarmTransfer. (2026, October 2). Setting up 802.1X authentication for Cisco IP phones: source note cisco-phone-8021x-setup-cdp-second-port. WarmTransfer. https://warmtransfer.net/knowledge/claims/cisco-phone-8021x-setup-cdp-second-port
BibTeX
@misc{warmtransfer-claim-cisco-phone-8021x-setup-cdp-second-port,
title = {Setting up 802.1X authentication for Cisco IP phones: source note cisco-phone-8021x-setup-cdp-second-port},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cisco-phone-8021x-setup-cdp-second-port},
note = {Source note cisco-phone-8021x-setup-cdp-second-port, checked 2026-10-02}
}