802.1X Authentication; Overview; Required Network Components - Cisco 7941G Administration Manual

Cisco Unified IP Phone
Initiator's Phone
Security Level
Nonsecure
Secure
(encrypted)
Secure
(encrypted)

802.1X Authentication

This section provides information about 802.1X support on the Cisco Unified IP Phones.

Overview

Cisco Unified IP Phones and Cisco Catalyst switches traditionally use Cisco Discovery Protocol (CDP) to
identify each other and determine parameters such as VLAN allocation and inline power requirements. CDP
does not identify locally attached workstations. Cisco Unified IP Phones provide an EAPOL pass-through
mechanism. This mechanism allows a workstation attached to the Cisco Unified IP Phone to pass EAPOL
messages to the 802.1X authenticator at the LAN switch. The pass-through mechanism ensures that the IP
phone does not act as the LAN switch to authenticate a data endpoint before accessing the network.
Cisco Unified IP Phones also provide a proxy EAPOL Logoff mechanism. In the event that the locally attached
PC disconnects from the IP phone, the LAN switch does not see the physical link fail, because the link between
the LAN switch and the IP phone is maintained. To avoid compromising network integrity, the IP phone sends
an EAPOL-Logoff message to the switch on behalf of the downstream PC, which triggers the LAN switch to
clear the authentication entry for the downstream PC.
Cisco Unified IP Phones also contain an 802.1X supplicant. This supplicant allows network administrators
to control the connectivity of IP phones to the LAN switch ports. The current release of the phone 802.1X
supplicant uses the EAP-FAST, EAP-TLS, and EAP-MD5 options for network authentication.

Required Network Components

Support for 802.1X authentication on Cisco Unified IP Phones requires several components, including:
• Cisco Unified IP Phone: The phone acts as the 802.1X supplicant, which initiates the request to access
• Cisco Secure Access Control Server (ACS) (or other third-party authentication server): The authentication
Feature Used
Meet Me
Meet Me
Mee tMe
the network.
server and the phone must both be configured with a shared secret that authenticates the phone.
Cisco Unified IP Phone 7941G, 7941G-GE, 7942G, 7961G, 7961G-GE, and 7962G Administration Guide for Cisco Unified
Security Level of
Participants
Minimum security level is
encrypted
Minimum security level is
authenticated
Minimum security level is
non-secure
Communications Manager 9.0 (SCCP and SIP)
802.1X Authentication
Results of Action
Initiator receives message Does not
meet Security Level and the call
is rejected.
Secure conference bridge
Conference accepts encrypted and
authenticated calls
Only secure conference bridge is
available and used
Conference accepts all calls
21