Extensible Authentication Protocol - EAP

* Extension to PPP
* Authentication Framework , not a Specific Authentication Mechanism
* Desired Authentication Method can be Negotiated  like EAP-TTLS, EAP-MD5, EAP-TLS,EAP-PSK
* In 80.11 it is used to negotiate Secure PMK (Pairwise Master key )

TTLS -Tunneled Transport Layer Security
PSK- Pre Shared Key

Codes :
EAP                                          Radius
1--Request                              1--Access Request
2--Success                              2--Access Accept
3--Response                           3--Access Reject
4--Failure                               4--Accounting Request
                                              5--Accounting Response

Authentication in Wimax System

Protocols  Stack :

  

Any real problem faced

I face a problem wehre RAw Socket was in promniiscous mode and lietening to all intefaces  though it was intended to listen on one Inteface .
// creation of raw socket 

 read_sockfd = socket( AF_PACKET , SOCK_RAW, htons(ETH_P_ALL)) ;
This stmt was success but not solving purpose
setsockopt(read_sockfd , SOL_SOCKET , SO_BINDTODEVICE , BIND_DEV , devlen+1 )


Solution
    struct sockaddr_ll sa
    int interfaceId =-1;
    struct ifreq ifr;

    memset(&sa, 0, sizeof(sa));
    strncpy(ifr.ifr_name,BIND_DEV, devlen+1);
    sa.sll_family = AF_PACKET;
// get interface index
    interfaceId = ioctl(read_sockfd ,SIOCGIFINDEX,&ifr);
    sa.sll_protocol = htons(ETH_P_ALL);
    sa.sll_ifindex =ifr.ifr_ifindex 
   bind( g_frame_read_sockfd , (struct sockaddr*) &sa, sizeof(sa));

Thing is we have to explicitly bind raw socket to socket address structure(with proper interface index )
Man page clearly says
By default all packets of the specified protocol type are passed  to  a    packet  socket.    To  only  get  packets    from  a specific interface use  bind(2) specifying an address in  a  struct  sockaddr_ll  to  bind  the
 packet    socket     to  an  interface.  Only  the    sll_protocol  and  the  sll_ifindex address fields are used for purposes of binding.

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 tcpdump  -d   vlan and ip  
tcpdump -dd vlan and \(ip or arp \)
tcpdump -d ether src 00:80:42:1B:1D:94 and vlan and \(ip or arp \)
tcpdump -d not ether src 00:80:42:1B:1D:94 and vlan and \(ip or arp \)