CISC-L2-000020 - The Cisco switch must uniquely identify all network-connected endpoint devices before establishing any connection - aaa new-model


Controlling LAN access via 802.1x authentication can assist in preventing a malicious user from connecting an unauthorized PC to a switch port to inject or receive data from the network without detection.


Configure 802.1 x authentications on all host-facing access switch ports. To authenticate those devices that do not support 802.1x, MAC Authentication Bypass must be configured.

Step 1: Configure the radius servers as shown in the example below:

SW1(config)#radius server RADIUS_1
SW1(config-radius-server)#address ipv4
SW1(config-radius-server)#key xxxxxx
SW1(config)#radius server RADIUS_2
SW1(config-radius-server)#address ipv4
SW1(config-radius-server)#key xxxxxx

Step 2: Enable 802.1x authentication on the switch.

SW1(config)#aaa new-model
SW1(config)#aaa group server radius RADIUS_SERVERS
SW1(config-sg-radius)#server name RADIUS_1
SW1(config-sg-radius)#server name RADIUS_2
SW1(config)#aaa authentication dot1x default group RADIUS_SERVERS
SW1(config)#dot1x system-auth-control

Step 3: Enable 802.1x on all host-facing interfaces as shown in the example below:

SW1(config)#int range g1/0 - 8
SW1(config-if-range)#switchport mode access
SW1(config-if-range)#authentication host-mode single-host
SW1(config-if-range)#dot1x pae authenticator
SW1(config-if-range)#authentication port-control auto

Note: Single-host is the default. Host-mode multi-domain (for VoIP phone + PC) or multi-auth (multiple PCs connected to a hub) can be configured as alternatives.

See Also

Item Details


References: 800-53|IA-3, CAT|I, CCI|CCI-000778, Rule-ID|SV-220649r539671_rule, STIG-ID|CISC-L2-000020, STIG-Legacy|SV-110269, STIG-Legacy|V-101165, Vuln-ID|V-220649

Plugin: Cisco

Control ID: e3a9df657594ff0a32f69b3732c8022422cdfd575b96f3b9772fdf249c6671c4