Configuring Port-Based Access Control (802.1x)

Terminology

EAP (Extensible Authentication Protocol): EAP enables network access that supports multiple authentication methods.

EAPOL : Extensible Authentication Protocol Over LAN, as defined in the

802.1x standard.

Friendly Client: A client that does not pose a security risk if given access to the switch and your network.

MD5: An algorithm for calculating a unique digital signature over a stream of bytes. It is used by CHAP to perform authentication without revealing the shared secret (password).

PVID (Port VID): This is the VLAN ID for the untagged VLAN to which an 802.1x port belongs.

Static VLAN: A VLAN that has been configured as "permanent" on the switch by using the CLI vlan < vid > command or the Menu interface.

Supplicant: The entity that must provide the proper credentials to the switch before receiving access to the network. This is usually an end-user work- station, but it can be a switch, router, or another device seeking network services.

Tagged VLAN Membership: This type of VLAN membership allows a port to be a member of multiple VLANs simultaneously. If a client connected to the port has an operating system that supports 802.1q VLAN tagging, then the client can access VLANs for which the port is a tagged member. If the client does not support VLAN tagging, then it can access only a VLAN for which the port is an untagged member. (A port can be an untagged member of only one VLAN at a time.) 802.1x Open VLAN mode does not affect a port’s tagged VLAN access unless the port is statically configured as a member of a VLAN that is also configured as the Unauthorized-Client or Authorized-Client VLAN. See also "Untagged VLAN Membership".

Unauthorized-Client VLAN: A conventional, static VLAN previously configured on the switch by the System Administrator. It is used to provide access to a client prior to authentication. It should be set up to allow an unauthenticated client to access only the initialization services necessary to establish an authenticated connection, plus any other desirable services whose use by an unauthenticated client poses no security threat to your network. (Note that an unauthenticated client has access to all network resources that have membership in the VLAN you designate as the Unauthorized-Client VLAN.) A port configured to use a given Unauthorized -Client VLAN does not have to be statically configured as a

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