Table 132 The Identifier field (1 byte long) is used to match request packets and response packets and to detect duplicate request packets. Request and response packets of the same type have the same identifier.

Table 133 The Length field (2 byte long) indicates the length of the entire packet, including the Code, Identifier, Length, Authenticator, and Attribute fields. Bytes beyond this length are considered padding and are neglected upon reception. If the length of a received packet is less than this length, the packet is dropped. The value of this field is in the range 20 to 4096.

Table 134 The Authenticator field (16 byte long) is used to authenticate replies from the RADIUS server and to encrypt user passwords. There are two types of authenticators: request authenticator and response authenticator.

Table 135 The Attributes field, variable in length, carries the specific authentication, authorization, and accounting information that defines the configuration details of the request or response. This field may contain multiple attributes, each with three sub-fields: Type, Length, and Value.

∙Type (1 byte long)—Indicates the type of the attribute. It is in the range 1 to 255. Commonly used attributes for RADIUS authentication, authorization and accounting are listed in 3.

∙Length (1 byte long)—Indicates the length of the attribute in bytes, including the Type, Length, and Value fields.

∙Value (up to 253 bytes)—Value of the attribute. Its format and content depend on the Type and Length fields.

3.RADIUS attributes

No.

Attribute

No.

Attribute

1

User-Name

45

Acct-Authentic

 

 

 

 

2

User-Password

46

Acct-Session-Time

 

 

 

 

3

CHAP-Password

47

Acct-Input-Packets

 

 

 

 

4

NAS-IP-Address

48

Acct-Output-Packets

 

 

 

 

5

NAS-Port

49

Acct-Terminate-Cause

 

 

 

 

6

Service-Type

50

Acct-Multi-Session-Id

 

 

 

 

7

Framed-Protocol

51

Acct-Link-Count

 

 

 

 

8

Framed-IP-Address

52

Acct-Input-Gigawords

 

 

 

 

9

Framed-IP-Netmask

53

Acct-Output-Gigawords

 

 

 

 

10

Framed-Routing

54

(unassigned)

 

 

 

 

11

Filter-ID

55

Event-Timestamp

 

 

 

 

12

Framed-MTU

56-59

(unassigned)

 

 

 

 

13

Framed-Compression

60

CHAP-Challenge

 

 

 

 

14

Login-IP-Host

61

NAS-Port-Type

 

 

 

 

15

Login-Service

62

Port-Limit

 

 

 

 

16

Login-TCP-Port

63

Login-LAT-Port

 

 

 

 

17

(unassigned)

64

Tunnel-Type

 

 

 

 

18

Reply_Message

65

Tunnel-Medium-Type