3com 2928 User Guide

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1-3 
Control direction 
In the unauthorized state, the controlled port can be set to deny traffic to and from the client or just the 
traffic from the client.  
 
 
Currently, your device can only be set to deny traffic from the client. 
 
EAP over LANs 
EAPOL frame format 
EAPOL, defined in 802.1X, is intended to carry EAP protocol packets between clients and devices over 
LANs. 
 shows the EAPOL frame format. 
Figure 1-3 
EAPOL frame format  
 
 
PAE Ethernet type: Protocol type. It takes the value 0x888E. 
Protocol version: Version of the EAPOL protocol supported by the sender. 
Type: Type of the EAPOL frame. 
 lists the types that the device currently supports. 
Table 1-1 
Types of EAPOL frames 
Type 
Description 
EAP-Packet (a value of 0x00) 
Packet for carrying authentication information, present between 
the device and the authentication server. 
A packet of this type is repackaged and transferred by RADIUS 
on the device to get through complex networks to reach the 
authentication server. 
EAPOL-Start (a value of 0x01) 
Packet for initiating authentication, present between a client and 
the device. 
EAPOL-Logoff (a value of 0x02) 
Packet for the logoff request, present between a client and the 
device. 
 
Length: Length of the data, that is, length of the Packet body field, in bytes. If the value of this field is 0, 
no subsequent data field is present. 
Packet body: Content of the packet. The format of this field depends on the value of the Type field.