EAP auto-isid-offset functionality is used for MACs that do not receive an I-SID attribute from the RADIUS server. The configured I-SID offset value is used to calculate an I-SID value for a Switched UNI (S-UNI) when the switch receives only the VLAN attribute from the RADIUS server (not the FA VLAN:ISID binding). In that case, the I-SID value is calculated as follows: I-SID = VLAN ID + configured I-SID offset value.